I've played battle mage, pure mage, 1h + shield warrior and assassin/rogue so far and I have to say my assassin is the most fun by far. I use bows, one handeds for backstabs and illusion magic and the variety of ways you can approach a situation is so fun. I can sneak around and 1 shot people while going invis, sit back with my bow as they run around trying to find me or even pop out my master level frenzy spell inciting an entire fort of bandits to kill each other while I raid their chests

I find the other play styles become so stale after a bit. Pure magic becomes a spam fest once you get magicka reduction items and I was impossible to kill with my shield warrior on master.