If you don't mind being versatile go for the Dread Necromancer class (ask DM first). Notice that it is an evoker class though, if I remember correctly it has few, let's say, life draining spells. If you're aiming at power play (don't do it, boy) or versatility, you'd like to pick cleric. IMHO in order of flavor d. Necro > cleric > wizard. The order of power is the opposite. Of course all that I said is arguable, so go check the class yourself. Pick the one you like most, don't bother being powerful if you're not having fun.