I'm pretty sick and tired of people calling Super Mario 64 a classic.  It's not.  Just because it's significant and influential in helping pave the way for future Mario titles doesn't mean Super Mario 64 is deserving of its classic status, or that it's any fun to actually play.  Super Mario Galaxy came along and pretty much improved every single aspect of Super Mario 64 so you basically no longer have to play this game other than to get a dated taste of mid 90's gaming history.  The only other possible reason someone would play Super Mario 64 is because they desperately seek open world exploration, and this is basically the only Mario platformer that can at least attempt to satisfy gamers with that particular appetite.  Not that I personally believe the game succeeds at the exploring aspect either.