Past: Genesis. There was something much more personal about it than the SNES.
Present: Probably the PS2, if you don't mind the occasional hardware issue. There's just so much to do with it!
Future: Nintendo Revolution. 360 seems to have cocked up, and nobody'll trust Sony any more after the whole DRM thing.
seriously id go with the PS2 seeing as i have one but occasionaly the bitch freezes up from overheating i dont know why 13 hours dosent seam that much...