Hard to say. N64 was great because it allowed a lot of innovation and there was a stronger focus on single player, since online gaming wasn't around. Goldeneye brought about some awesome split screen tournaments when I was in high school and jr high.
Then came Xbox and the original Halo which was similar. great story, very fun and awesome system link matches. And they introduces Xbox Live shortly after which imo changed console online play like Goldeneye for the shooter genre and Mario Kart 64 for arcade style racers.
All comes down to what you like. I think some of the older members here have a bigger connection with older consoles just because they were so revolutionary and they grew up on it or lived on them for so long. When N64 was first out there wasn't really anything like it for the package you got.
Some of the most use I got was for my N64. Goldeneye, Super Smash Bros, Mario 64, Mario Kart, Zelda, etc.
I also had a SNES which I played to death. Super Mario World was and is still a fun and addictive game.
Having said that, from a pure fun factor and the fact I can get online and play with any number of people at any point in time I like my 360. Graphics are great, online multiplayer is great and you can still find some really good single player games. Mass Effect for example. There is just so much already created its tough to be original like back in the days of the N64 when there was still so much to be made.