My wish list:

1. Make it 10 times harder to accumulate gold, so it actually feels like an accomplishment when you can buy and decorate a house
2. Nerf the Ench/Blacksmithing bonuses so it's possible to use time on the professions without becoming a god with the armor/weapons you make
3. Flesh out the NPCs with options for more small talk to define their character. A ton more NPCs should have journals like Kodlak
4. Make it possible to have children with your spouse. Like another post here described; an option to ask your spouse to go to bed (and the screen goes black), and then some time later there's a child or two when you enter your house again.

Put limits in enchantments/potions (no more than 75% fortify magic, 100% smithing etc), possibly increase the armor cap
Make it so that NPCs only have a smalll chance to talk to you unless you click on them.
Associate skill level with raw skill power, and perks only with specialisation/added bonuses.

I'd ask them to make the alchemy ingredients and the value of alchemy potions created by them have a stronger corealtion. Currently, there's extremely common ingredients that can be used to make some high value potions. I'd also have ores replenish quicker, as the play-style where a player only uses what he finds (live off the land) is poorly supported by this game. It assumes we're buying what we need from merchants. I would also make restoration skill up a bit faster... maybe as much as twice as fast... for the healing spells.

1) Give you an option to talk to the horse vendors to "Stable" your horse until you come back. Nothing like being out and having your horse killed by some random dragon when you didn't want them along to begin with.

2) Allow your house to reset all items so that if you accidentally pick something up you don't have to look at bare walls/tables.

3) Make food a bit more varied in what different finished foods do for effects. (Small buffs to different stats/skills, etc)

then why a cap on armor? Why a cap on perks or levels? Or skills?

1. add perk points (so we can get the fun perks)
2. change the dammage and armor formula o get a linear behavior instead of exponential behavior
(this is what cause the end game imbalances)
3. change single-creature spawner by imperial-quest style multi-mob spawners to improve challenge and dungeon dynamics
(many dungeons are cool yet so empty)

1. Allow underwater combat

2. Show active effects on screen & not buried in a menu (at least for the effects that have a time component to them)

3. Fix dialogue UI on the PC to work properly with the mouse.

OH HECK NO UNDERWATER COMBAT!

1) Remove all extra objects (zero value) in the world that slow down the saving and mess up the game: i.e. remove all linen wraps, embalming tools, lanterns, shovels, spoons, cups, bowls, etc. Also do away with the useless food system in the game...disable the cooking system entirely too. That would remove 1/2 of the objects in the world and would solve all the lag and saving issues in the game.

2) Totally rework the economy of the game by making 1/5 of all weapons and armor left on a dead body “Broken & worthless” That way looting corpses and selling gear at stores is rendered useless as a quick way to make money. It makes buying at a store not merely selling a possibility. If you had to buy 4/5 of all weapons and armor that would make the money you make far more precious. Questing would become more interesting for the story and treasures not merely for the mundane corpse looting.

3) Add a system where it is possible to own a horse, cart, storefront building and run your own store in the game. The horse and cart would allow you to move 2000 lbs of ore, armor, weapons, clothing, etc anywhere you want. The storefront if you choose to purchase it would allow you a nice way to display you items in an interactive way. NPCs would come into you store to purchase items and depending on how good your items are and how good you prices are they will shop more often. That would allow you to ROLE PLAY a storeowner in the game and even make merely crafting/selling items a viable way to play the game.

The ability to drop quest items.

Working on them now with SkyEdit ...

Much, much less gold, tougher vendors, vendors with only basic items.
Much less frequent enchanted or special materials equipment.
My 20-25 steel weapons to add more variety in basic weapons.
Sharper, more deadly combat
More diverse level scaling to keep weaker creatures in the game longer and add stronger creatures earlier.

Most have been mentioned so I'll say

1. Rock climbing. My character can do all sorts of sneak stuff, is awesome with a bow, and pretty good in melee combat; but he can't climb a rock that's waist-high.
2. Already said, but more varied types of bad guys.
3. Already said, but the ability to play the quests from the evil POV

Seemed to me like they were added to help hype the game in trailers, but ended up being detrimental to gameplay. That said, they're kind of neat when you see NPCs do them to eachother in real time, but as the PC when they jerk your camera around and/or slow time it's really awkward and ends up being more of an irritation than anything.

1. hardcoe mode

2. Smarter companion AI

3. Dragons dont attack everytime you teleport

This would ruin the immersion of the game I feel. I love being able to see and interact with everyday objects in the game like spades and paper. They may not have any use but they are essential in making the world we're playing in seem real and believable. I think there would be a lot of complaints if all the items that were useless were removed. Toning it down a bit I could understand, removing completly is asking too much. As for the cooking aspect, I actually like it. Roleplayers use it often enough and I use it for meals that can regenerate health. It gives the player a bit more freedom in the game and I think its a good idea, I just wish they had done more with it than what we have. A skill tree would have been great, or even a perk in an existing skill tree that makes the food you cook a bit stronger.
I dont think making the weapons and armour worthless would be a good idea, as people would just leave them and then go to smithing etc. I think the items need to be more valauble at later levels, meaning that the more powerfull potions and armour I think should be worth more and mean they are more expensive. That would mean that the expensive items need to be rarer, or impossible to find outside of markets or specific events.
This I kind of agree on. I think you should be able to own a horse and place it in a stables when your not using it and I think we should be able to own a shop, but I dont think being a store owner would work in a single player game would work. That only ever really works in a MMO and TES is not a MMO and should not become one.

First, not everything on the side of the road wants to kill you. Some witches and mages and even bandits will leave you alone - not all of them, granted, but a noticable amount - and will stay neutral unless you do something to tick them off. After all, not all of them should be set to "kill random person on site", some should be smart enough to know "if I do that, people will come after us and we will be killed." Now, if you enter the area they are watching over, then yeah, they'll aggro, but just getting near them? What if I wanted to chat? Or join their group? Or hey, witches need mats for potions, right? They could send me on radiant fetch quests!

Second, wider variety in equipment design. What do I mean by this? Well, look at Steel Armor. You have several different types to choose from, and can mix and match. Cool, right? So why can't any other armor do that? Why are hooded thalmor robes always enchanted with the same enchantment? Why can't they be more varied, like the other magic robes, and even come in un-enchanted varieties? There'd be nothing that is better or worse than what's already there, but there'd be more variety within it.

Third, better UI. Especially the Journal. I like how Morrowind's journal, you know, actually looked like a journal. A lot of my issues here are aesthetic ones, but some are more practical, like changing how things can be sorted. Apparel → Sort by type. Now I don't have to hunt everything down! Favorites → Sort by type. Ditto! Is it so hard to not have an alphabetical sort all the time? Sorting by value isn't always the best idea, either! Let us have the ability to custom sort based on Type, Alphabetical, Power (attack/armor value), and Cost (how many Septims/Magicka cost).

1 - Removing underwear from the Khajiit and Argonian characters, even if what's underneath remains "tame". I like the appearance of the unbroken fur pattern.

2 - Remove the need for helmets from the Light Armor perks

3 - Add a quest to Take Down the Thieve's Guild!

I have to this topic, where I posted 6 UI improvements. They're all fairly easy to implement.

http://www.gamesas.com/topic/1271995-nearly-indisputable-ways-the-ui-could-be-improved-by-a-patch-without-disappointing-anyone-who-likes-it-the-way-it-is/page__fromsearch__1

1. Longer guild questlines, even if it means more menial tasks at the beginning. That's how it should be! And also more guilds in general.

2. At least double the amount of NPCs

3. More travelling options besides carriages

1. Make essential characters killable by the player. And killable only by the player.
2. Like Scow mentioned a few posts before, make a Destroy the Thieves Guild quest.
3. Smithable Horse Armor of all different types of armor materials.

1. Keep the Main Quest for casual gamers so they can get their 20 hours worth and move to the next game. Make guild quests longer and require the player to reach a certain level and or reputation before they can advance in rank. Make the guilds an effort to progress through for your hardcoe players that like to sink 100s of hours into your game. Both camps win.

2. Re-invent the difficulty settings. Make where the player can chose certain gaming conditions at the start of a new game that will effect the entire playthrough (such as choosing whether essential NPCs can die or not) Power to the people!

3. .......

Problem with the difficulty settings is pretty ingrained into the rest of the game. Some things are absolutes, others percent based, and so high difficulty makes some things considerably weaker while others remain at default effectiveness. An Illusion spell does the same thing on novice as it does on Master, no added difficulty there, while a damage spell is half as effective. Similarly, a paralysis poison does the same thing on master as novice, while a damage health potion is half as effective. You could sort of argue for damage mitigation as well - kiting avoids all of melee damage regardless of difficulty, while your health relative to damage becomes much weaker.

There's little consistency in the degree it increases difficulty for different characters.

1. Don't restrict my ability to climb a 6' face that I could EASILY climb IRL. All mountains should be "climbable", progress should just be slower.

2. Horse health imporvement and/or horses flee combat, but are "recallable" with a whistle or some such.

3. Why oh why is it that open air assassinations in towns almost ALWAYS lead to a bounty even when NO ONE is anywhere nearby, sneak is successful, etc. But I can kill a target in the next room while his/her family is in an adjoining doorless room and no one hears a thing.

Honestly, if its something easy I will do it myself with a mod. I want the big stuff changed... So magic being a huge thing, and adding some cause/effect in the world.

The only easy thing I can think of off-hand would be to remove the whole HDR dimming when switching from bright to dim lights. My eyes already handle this all by themselves... I don't need the game to triple the effect.

The most desirable "Easy" thing I can think of would be to be able to fast travel to the inside of your home using the world map.
It seems like it would be simple to add a tab to the map at each location you can buy a house.
Click on the tab and it would put you directly inside the front door of your house.
No telling how many hours of my playing time that would save.
Something else that would be real nice would be to be able to fast travel from the inside of your house to any of the fast travel destinations without having to step outside then fast travel.

The time waiting for the computer to load up different locations as you fast travel isn't quality play time and should be minimized.