My sorc, Kittinn, is/was the most fun to level up. My first character that didn't get deleted by level 2. Of course, I didn't know about the wonders of UMD (when I played PnP, UMD was a percentage roll for Thieves based on Thief Level), so she is unable to do a lot of things that other sorcs can do, but she lays down some wicked damage spells.

It is hard to solo with a sorc at low levels, but easy to get a group, which was perfect for me while I was learning the low level content. Fast casting and lots of manna is a recipe for fun. Plus, casters get to be the hero a lot, either taking out the end boss with magic missile, PKing the beholders, FODing the orange names, whatever, its great. I especially like the AOE spells. It is particularly enjoyable to watch the melees run into the middle of a pack of mobs then throw a fireball in there and watch the mobs all die simultaneously. Plus you can teleport all over the game, which is nice.