I don't know the psp games always seem "sharper" due to the high resolution LCD screen. I know the wii version will have progressive scan (hopefully); but all in all you cannot go wrong with either version.
1) Wii has best textures and for some a more unique control setup.
2) PSP has sharpest image quality due to the high fidelity LCD display.
3) PS2 is close to the wii in the graphics department and may end up with the easier of the control schemes.
(Imo ofcourse)