I think I'll join the SNES or N64 brigade. The first console I owned was a SNES with Mario Allstars - and then Donkey Kong and Starwing blew the doors off for me in terms of games I loved and replayed.
The N64 launch was probably one of my most anticipated moments as a kid. I used to go out to a big Toys R Us to play Super Mario 64 before the console was properly released. Then Goldeneye, Blast Corps, Mario Kart 64, Ocarine of Time... It was just a great period of gaming.
Now on the 360, I buy stuff occasionally when released, but like others have said, I really can't justify £50 for a game that has only about 8-10hrs of single player time in it (MW2 anyone?). I miss the really fun pick up and play games of the PS2 era (SSX, MGS) and the longer story development games of years gone by like Resident Evil 2. I'm hoping Alan Wake might have a little touch of that, but I do look back and think I could never spend as many hours gaming now as I did then.