I don't know what you guys are talking about. I'm playing a pure mage Dunmer and it's awesomely powerful. At low levels, warriors such as Draugr would just swing their axes and miss while I backpedal/circle-strafe and hit them with the flamethrower spell. If they hit me, I'd backpedal and heal up. If I run out of magicka, I'd run away and wait for it to charge back (which is sped up by Necromancer robes you can get right off the bat.) Now I can one-shot Draugr and bandits with Fireball at level 16, and I think I'm two-shotting
soldiers with it. The warrior AI is [censored] against magic. My biggest challenge has been fighting other mages or magical creatures, but they can be beaten if you start using lightning spells before they do.
Perhaps I just had too much experience playing the Pyro in TF2, though.
Oh please. You aren't some uber skilled player that knows some secret tricks that the rest of us don't, so we are saying something is underwhelming when it's not. Instead of reveling in your awesomeness, how about this; make a melee character that dual-wields. Walk up to ANYTHING, even a named and power attack. Watch it either die or the health drops to 1/3, and this is well before you have +100% damage. The disparity between Destruction magic and melee is outright sickening. I just forged my Ebony set with two Ebony swords and each do 48 damage. I'm still missing +40% worth of upgrades and those aren't even the top damage swords. With how fast I can swing by alternating the mouse buttons, I can keep humaniods in stunlock indefinately and one power attack deals so much more damage than a 100 skill Destruction caster could dream of.
http://imageshack.us/photo/my-images/440/ebonyn.jpg/
Gamgee is correct about how it's setup for CQC since they always make a bee line towards you. Especially in dungeons where often there's not really enough space to kite the way you would need to. Hell, even in the same armor, you still have to kite, yet as melee you don't because the enemies drop so much faster AND you have a hell of a lot more health.
40 Sneak, most of the lower perks +35% sneak. The silent light armor perk. I backstab one random bandit for 6x damage and it took him down a quarter health.

Wow, don't spend it all in one place. Then every enemy in the cave instantly knows where I am and bull rushes me. As a Warrior I can just go in axe swinging and be infinitely more effective, laughably easy compared to all the preparation needed to set up even one stealth attack that won't kill anyone anyways. I'm also on the hardest difficulty where stealth and magic just don't scale. Then I reloaded, set the difficulty to adept and lo and behold the scenario played out the exact same way.

I don't know what stealth video's you've been watching but odds are they had the best gear and were playing on the lowest setting and with a super high skill to make themselves look badass. At that point though as mentioned any class will be badass.
Dunno what kind of dagger you are using, or if you've heavily invested in the one-handed damage bonus, but it sounds like you're missing something. A dagger backstab should be doing MORE damage than a power attack, not less than half. You also don't have the later stealth perks. Like I said, it's slower to start, but faster to break the game.
I disagree.
I find it unstoppable even on master when your pumping out Daedra in one hand and slaying the enemy with Master destruction spells in the other.
Thank you for unintentionally proving my point.