here is a little game that myself and a friend used to play when we were young back in the 80's: the idea was to 'cast' a movie star in a role in a film that we wanted to see. since then, some have been made but not all were any good! anyhoo, I'll just give you a few examples and let's see if anyone else has had similar ideas...
MEL GIBSON as 'Wolverine' in X-MEN
CHEVY CHASE as INSPECTOR GADGET
actually I must mention this one also - we spent a whole day I think casting ACTION FORCE: THE MOVIE (Action Force a.k.a. G.I. JOE) so this bit is for the geeks!