I really like Telekinesis and Transmute the best, both of which are Alteration spells. I like that I can move things with my mind with Telekinesis, great for fooling around or throwing something at your enemy.

Transmuting is a fun non-combat spell, turn iron ore (which costs almost nothing) into gold, collect precious stones and make fine jewelry for myself and to sell. In fact I make most of my money from selling jewelry.

I'm at level 52 but I think I'm actually going to start taking the alteration perks.....I've been using alteration the entire game, I might as well master it. I'm looking forward to getting the paralysis spells.