I prefer the newer figures. My favorite wizard is the Good Wizard. I like his printed legs with the pouch, vial, etc., and his printed hat. I wish he would have been more widely available in the US. Tied for second favorite is the Evil Wizard and Witch, for the unique printing on legs/dress and torso. I don't have the Troll Sorceress yet, but i'm sure she'll move into a three-tie for second once I do, also for the printing.
I think the most useful wizard is Majisto. If I could have multiples of any wizard, it would be him. Swap out the hat for hair, remove the beard, and/or change the head and you have many possibilities for different peasent characters. Without the pointy hat and wand, nothing on his printed torso really identifies him as a wizard.