Pal/Mnk/Sor
I'm currently playing a Pal1/Mnk1/Sor X.
My saves are nice, but I'm nowhere nere the power of our level Wizard X+2. When he was casting level 3 spells, I was still playing with Magic Missile.
Mostly I get used as a decoy, due to my High AC, Extremely high Saves, and the fact that I look like a caster, to draw attention away from the Wizard. I also am the back up artillery, and eventually I'll be used as the escape plan, when I have some teleport spells, to get the party out of trouble when everyone but me fails their saving throws.