3x size world map, Skyrim is way to small.

I would love more trigger mechanism for traps in dungeons and outside.

I was going to say 2-4x the size, but I suppose 3x makes for a good average.

More quests to do with Orsimer!

Better written quests ala FalloutNV, actual consequences after you completed main quest ( e.g. people actually praising you for saving their collective asses )

More mounts, horses are getting boring xD

or

New weapon types? Wands,spears,etc

50/50 for either one dwemer ghosts or skill level dependant location damage i guess flip a septim to decide.

I can't limit it to 1 thing..

1. spell making/variety of spells
2. variety of enemies. We have humanoids and animals, and undead humaniods... oh I forgot dragons. All enemies require the exact same tactics to kill, except for elemental weakness/resist, and dragons that won't land. Morrowind & Oblivion have unique enemies that change things up... especially Morrowind. Spriggans didn't heal, they resurrected constantly. There were numerous enemies that could not be hurt by standard weapons, and others that caused status effects.
3. NPCs mages using ALL the spells. Wouldn't it change things up if you were sneaking and when an enemy knew someone was there but wasn't sure of your exact location(eye partially open) they used candle light, mage light, and detect life to find you? Same goes for illusion spells working on you. Frenzy makes everyone look like a dremora. Fear makes your healthbar show 1 health no matter how many health potions you take(obviously you have regular health, it just shows the 1 no matter what), and all the enemies appear as having full health and more of them. Calm makes you sheath your weapons/spells until you get hit or the spell wears off. Enemies could use bound weapons... they sure did in Oblivion and Morrowind.
4. Werewolves... that are not part of a major questline. I want to wander into a dungeon, be fighting some pitiful bandit and then he suddenly turns into a giant monster. We are in Skyrim.... there are suppose to be 'bad' werewolves. Would also be cool if there was a dungeon that was packed with werewolves and the silver hand or the vigilants were invading when you came in. Ditto for a vamp dungeon.
5. Better quest lines, longer quest lines.
6. Bigger everything.
7. Faster horses to explore that bigger everything.
8. Bonemold armor. Dunmer do not wear Elven armor, they wear bonemold armor. All the Dunmer that came to Skyrim following the Eruption didn't bring a single suit of bonebold armor?

Better Vampires (completely redone).

id add some form of medevil fantasy dwarfen made train system

Element manipulation (Bending for you Avatar fans )

Vampire questline. And some more spells, they're kind of lacking.

Seeing as PC user are already able to put in whatever they want, I'll assume you're talking to console players. In that case, I want the ability to create mods and add them to our world, or maybe find a way to add mods from the PC to consoles.

Actually, we're not able to put in anything we want. There are limitations.

More stuff to do underwater - combat underwater even.. ability to sail a ship or buy one, hire the crew and take a 30% cut on profits. Sea monsters!

Swinging on ropes and vines.

Khajiit that I could actually marry.

More Conjuration spells.

What ever happened to my sweet Spider Daedra and Clanfears?

Better guilds.

hardcoe mod, only this is how I would do it.

Semi-essential pcs turn into non-esential
essential pcs turn into semi-essential

(semi-essential basically means they are essential until the Player inflicts the slightest bit of damage, they they temporary lose that status until either they die or the battle is over.)

Arrows carry weight.

Niether health nor magika nor stamina recharges unless you eat food, drink water, or a potion

You have to sleep regularly, but food and water is not a necessity

You cannot fast travel unless you are well rested.

You cannot turn off hardcoe and turn it back on again
So, its slightly different than FONV

more weapon types and magic

Good writing.

Expanded storylines for the Guilds, and by expanded I mean story lines that aren't pure drivel. The guilds had some sparks of ideas but never actually capitilized on any of them.

Fighters Guild:

Would have been better that werewolves in Skyrim were wild beasts not just located in the quests. That way you could also have a bunch of quests that focus on the Were companions hunting out of control werewolves in order to safe guard their homeland. And have a select few missions where the were in question joins the companions *see below story* and become a follower, when you shift they do aswell to give you a sense of comradery.

* You get sent on a mission to find another out of control werewolf and to kill it. You find that its targeting a specific family in a farming community.

• Option 1 - Kill the werewolf mission ends with you getting paid by the farmers for ridding they're farmlands of the beast.
  
• Option 2 - Investigate why it's only going after the one farm hold, discover that the farm used to belong to the werewolves parents but they died under suspicous circemstances. You figure out that it was the current farmers living their (Husband and Wife) that murdered them and faked a deed of ownership.

In order for you to conclude the 2nd option you either have to let the werewolf kill the people then join the companions or use a persuasion check to convince him/her to let them live so that they can rot in jail like they deserve.

College of Winterhold:

Make a long (8-15 missions) quest chain where the college helps Winterhold rebuild earning some trust of the people back not only in Winterhold but all of Skyrim. Imagine seeing each of the mages use their abilites to help people out. A smithy making tools with an flame atronach keeping the forge burning. The destruction mage teacher clearing the land of snow, rock and trees where a new building is going to go. The restoration mage (the one who always complains about people underestimating her skills use) erecting a huge ward over the town so people can work without freezing in the blizzard that rages outside the ward.


Thieves Guild:

To prove their reputation and make it known that they have truly returned to form you embark upon a quest chain to replicate what happened in the elder scrolls book http://www.uesp.net/wiki/Oblivion:Purloined_Shadows. The quest involves stealing several items scattered Skyrim.

The thieves guild chooses to honor Nocturnal on the aniversary of Emer Dareloth, the first guildmaster theft of the Grey Cowl of Nocturnal by stealing into another Daedra Lords realm and stealing a priceless artifact to present to her at her shrine, she then rewards the guild leader who led the theft with the Bow of Shadows. (When you draw an arrow in the bow you turn invisible but when you release it you lose the cloak)

• Item that opens the door to another Daedra Lords realm.
  
• Something to hide you from that Lords sight. (from knowing your in their realm)
  
• A device to store the powerful stolen artifact in to keep it safe and hidden. (its power is a danger to you, also hide it from daedra lord until delivered to Nocturnal.)

Along the way you have to bribe, persuade or threaten to get the information regarding the locations of these items or do a favor to someone in return for the info.

i want this
actually, there are some big limitations. also, there is a risk of crashes, badly coded mods can do major damage to saves, not all of us choose to use mods and not all of us have good enough internet connections to be downloading much.
plus, mods for console are unlikely, as i have dheard that microsoft and sony are annoying about user-created content.
i hate it when console users say things like this "PC shouldn't get it, they can mod it". usually it is stupid because it is something that bethesda could easily add to all platforms (eg a marryable khajiit)

Tongs.

Maybe the Fork of Horripilation...