Depends how important costumes in cutscenes is. If it is; then get the PS3/360 version. Best looking version by a mile. If costumes in cutscenes isn't important; then get the PC version with mods. The mods make the game look crazy good.
As an aside: I've always felt the Wii controls for RE4 were terrible. You could only rotate the camera with the nunchuk analogue stick. It was always backwards to me, especially if a zombie is mostly off screen that's pretty near you. It's a pain to actually aim to it. NOW, if it had the Metroid Prime controls...








