N64 was probably the best. Hit right at the prime video game playing years of my life, though, so that probably plays a big part of it.
I remember being blown away and made a little motion sick by the swimming levels in Mario world.
Goldeneye was the first multi-player fpshooter. Billions of hours of wasted youth went into that game, nobody could get enough of it. We'd play it for as long as possible, skipping sleep. Mario kart 64 was also very strong. Mario tennis was a fantastic game to play with a few friends over some drinks before going out.
1080 snowboarding also felt like magic , the actual feel of carving a snowboard, in a game.
Donkey Kong, wave race, super smash bros, starfox, killer instinct: gold.
All great.