Magic, as I find that Warriors are to... "samey". You don't have really any tactics other than block and attack. I do find these characters fun, but Mages are better for me. Stealth doesn't go to well for me. Mixing combat with stealth, (Like Ponty's Nightingale Swordsman) is fun, but pure stealth is just boring.
My character, an Imperial called Jasper, started as a warrior, went into a stealth and came out a mage. Thanks to the Dragonborn skill tree removal.
Jasper now is a Destruction Warlock, (For all you WoW fans), which the main set up is Destro, Alteration and Conjuration as primary skills, while Restoration, Alchemy and Enchanting are my minor ones. If you were wondering, I use Non Hooded Thalmor Robes and Thalmor equipment. Sort of like Warlock - Dark Summoner build. Well, that was quite a post...
I enjoy stealth warriors, personally. Focusing on Sneak, Light Armor, Block, One-Handed, and Archery gives you the freedom to approach (or avoid) combats in a variety of ways. If the pure mage relies on his magicka pool, the stealth warrior relies instead on stamina and tactical positioning. It's a tricky build to play, especially in the early levels where light armor gives negligible protection, but it quickly becomes a very strong all-around approach to the game.
It is hard to tell, I've already played Destruction mage, 2 handed brute, sneaky bastard and I enjoyed all of them. But I must say the one that I prefer the most is a conjuration mage :) I played a lot with Diablo 2 and I loved to play the necromancer (summoning ). In Skyrim, the situation is the same :)
Pure Mage. I was never good at archery weirdly enough and I could easily play a warrior though it doesn't have as much appeal as being able to use a wide arsenal of magic. From being the Gandalf/Dumbledore wizard to a scholar, being a mage is limitless. Especially when you go around hoarding Daedric artifacts!
Knowledge is power.
I've got a really odd combination in an Imperial I made to be the "offspring" of Heath Ledger's Joker and Alice Pleasance Liddell (Alice from the Lewis Carroll stories.)
Her playstyle changes: she mains a Ebony Bow she found, plus dual wielding Firebolt spells, also a Steel Warhammer she enchanted with Soul Trap (she also has the Black Star!); she loves dropping into stealth and striking unseen!
Warrior is my favorite. There's just something about standing toe to toe with someone and hitting him till he stops moving That being said, I've enjoyed playing each of the archetypes and several combinations. One I really had a blast with was a sneak mage using mostly illusion and conjuration. Making an entire bandit camp kill each other without them ever knowing I was there is just too much fun