My first character was a pure destro / resto mage, but that ended up sucking so I stopped. Now I'm playing a bow / dual daggers assassin character.
Yeah, I'm finding out the hard way that a pure destruction mage has very little defenses. But by now I can kill most warriors before they enter close combat (and I have frost cloak for when they do) and against mages, there are wards. All of that just sucks magicka so badly, it hurts. I'm a killing machine in short encounters, but for longer battles, I rely on my flame atronarch to buy me some time to regenerate magicka.
But I've started a second character, which I intended to be a sneaking archer type, but I've already started doing too many other things, I fear. I may have to start over with her (yeah, I decided to make a norse warrior queen. I just liked the female norse better than the male).