[geRV]

I wouldn't really say theres been a console which defined THE massive leap in graphics. Nes to snes brought about big improvements in graphics as did mastersystem to megadrive (genesis). Snes certainly was the more impressive of the 2 later on with games like donkey kong country. Nintendo 64 introduced the first proper 3d game in mario 64, but before that snes and megadrive had games like starfox and virtua racing which was the start of games becoming 3d (long before the playstation ever hit the market).

Its impossible to say really because all the consoles represent different eras of technology.