Most common things round 'ere are GB games / consoles, closely followed by MD / SMS (usually sports). Also the occasional DC / Saturn game (again, usually crappy sports games).
SNES games are rare, NES far rarer. I have seen PCE games once, in a dedicated retro games shop (same one I got loose Chaotix for £15).
Mostly there isn't much of anything to be had, though. Of course I expect it's just that everyone else gets the stuff before I do :P

