Tricky one...
I've been playing games since 1980 (with some breaks obviously!) & still play all the old games with emulators for just about every console: Arcade (MAME) N64, Megadrive, SNES, NES, Atari, C64, Spectrum etc etc
Modern day:
1. Pro Evolution Soccer 6 (PS2)
2. Colonization (PC)
3. Super Mario World (SNES)
4. Championship Manager 93 (PC)
5. Mario Kart (DS)
Retro Arcade:
1. Bubble Bobble
2. Double Dragon
3. Kung Fu Master
4. Ghosts N Goblins
5. King Of Boxer (aka Ring King)
If anyone would like any help on how they can play any old games on their PC just let me know...