The Wii would be awesome for GTA, swing the wii-mote to hit with objects or your fist. Use the nunchuck to throw granades or other things, Wii-mote point and shoot with the trigger for guns. Wanna drive a car steer wit the wii-mote and nunchuck like ur holding a steering wheel. ooo the possibilities!
As I really love Point&Click-Adventures, I couldn't help but think that the wii is specially build for them. I would die to play one of them on this system.