There are probably many threads like this, but hopefully the message gets through when more people are saying the same thing. Anyways...
Overall I think Skyrim was at least in beginning pretty enjoyable, until I released how overpowered and unbalanced so many things in this game are.
Why waste countless manhours for world, dialogue etc. and completely ignore the underlying game mechanics?
Stat system is completely broken. 100% magic immunity? Free casts? ARP to ignore enemy armor so you can whack everyone like they were mages wearing only a robe?
Money has no value. It is too easy to come by so you can get whatever you need from merchants without care.
I've never had any of these problems. If you dont want to become immune to magic, then don't. Simple as that. It's not like it's EASY to get any of those things...unless you're really OCD. As for money, I have no idea where you're coming from with that, I never have enough money xD. The most I ever had was 9k, and i used up 5k of that right away when i bought a house...and there are much more expensive houses out there!
Gear is too easy to get. I was running around in orcish plate when a High Elf in a middle of nowhere attacks me. He dies to few hits and I notice he was wearing FULL Ebony Plate set...
Sounds like random good luck to me. I've never had anything like that happen! Odd that even with full ebony he dies to a few hits, though.
Crafting (smithing, alchemy, enchanting) completely breaks the game if you choose to use them.
If you choose to max them. All of them. At that point, aren't you supposed to be on an equivalent level as the God-Heroes of old, anyway? At maxxed stats, you SHOULD be able to get ludicrously powerful weapons, because that's as powerful as they'll ever get!
Too few enemies. Only 1-3 come at a time, no challenge. 5-10 would be something. There are many rooms where mobs spawn in pairs or something like that... silly. Why they won't come all together?
If you were getting swarmed all the time it would be boring. I once ran into a dungeon that had waves of 3-5 higher level draugr coming at me while a ridiculously tough necromancer shot ice spells at me from a distance. It was super fun, but I also died a lot when I did it, and I wouldn't want to do it all the time! But it certainly exists

Vendors sell everything. I was wondering how I'm going to get a Daedric Plate set but then I realized the cottage smith next door has a small mountain of Ebony ignots stashed and the apotechary sells Daedra Hearts like they were potatoes.
The merchant gear scaling has always annoyed me, but it's always been like that, as far as I know. I doubt it will be changed, but you could always send an e-mail to bethesda, it couldn't hurt! At the very least, mods will probably fix it soon.
Also I could mention that dragons are a joke etc etc. Anyways, if I wanted a challenge I'd need to do at least these things:
Choose a race with useless racial
Don't use crafting
Don't buy anything from vendors
Use some crappy low dmg weapon like sword instead of maces
Don't use shield which negates all melee and ranged damage
Dragons have too little health, that's true. Most races dont have that useful of a racial bonus, so it really doesn't make that much of a difference. Crafting, again, is just fine till you get near the endgame. Vendors are also fine until the endgame. My dual wielding sword redguard girl can take out a dragon in 6 second flat. And using a shield only works in one direction! If you got attacked by two dragons, you'd be in a bit of trouble ^.^
etc. etc.
For TES VI please look at how things are done in other games.
Don't give crazy racials like 25% magic resist, heck, even 2% is OP in some games. Limit resists to max 75% like in other games. Being able to completely ignore enemies with 100% resists is just silly.
Don't make some specific weapon type way too good compared to others
Don't let vendors give out best materials/items in the game.
Stats like armor rating should have diminishing returns, like after each stat increase the net effect is smaller and smaller the more you get that stat.
More variety to combat. Now it has 2 moves, fast and slow hit.. not very innovative. Also enemies only do damage, they don't use any nasty spells like fear or anything on you.
25% magick resistance isn't all that much, honestly. I believe its the most powerful of any racial ability, probably, but at least its no longer 50% like in oblivion =P . Maces aren't all that good. They're good against stuff with armor, but fight something without armor and you'll do significantly less damage than a sword or an axe. And an axe will always do more damage in a prolonged fight. Each one is good for different things, essentially...maces for armored enemies, swords for burst damage, axes for big boss fights. Agreed on vendors. Send an email. Armor rating should, indeed, provide diminishing returns. I was under the impression that it was just a health multiplier...IE, 40 armor=1.4x health. Apparently i was wrong, which is unfortunate. I would have hoped they would have learned by now. Oh, well.
Also, combat has power attacks in all directions, didn't you know that? That's 4 moves right there, just for close range combat. You want more? This is an RPG, not a fighting simulator!
I don't know if the designers in Bethesda have played challenging games like Demon's Souls or games with innovative game mechanics, or well balanced games like Blizzard's Diablo 2 & World of Warcraft... but they really should play them and look at how games are done in this millennium. Completely broken and boring game mechanics may have been OK when Daggerfall was released, but not today.
What you fail to realize is that those games are aimed at an entirely different audience. People playing Elder Scrolls games looking to do whatever they want, and limitations only annoy us, and tend to end up getting modded out. In my mind, the less limits the better. I personally think it would be great if there were no skill caps, and stuff like daedric princes manifesting themselves on Nirn happened at that point. A nice brawl with a god seems like a load of fun, to me.