Wizard:
More choices. Because you can unmemorize spells at will, you're never short of options. If you're faced by someone with immunity to Time Stop, unmemorize your Time Stops in favor of something else. Etc.
You get an exp hack
Charisma, for talking to other people, can be easily gained early on with the ring of set your CHA to 18 (forgot its name).
Sorcerer
More spells. To make up for the lack of choices, the Sorcerer gains more spells to cast in general, making a far better nuke than a Wizard.
So, basically, the choice is between whether I want the caster part to merely enhance my combat abilities, or whether I want a tank/nuke. I'm not sure what I want, so I'm asking everyone here which one is better