Super Mario 64 is, of course, on Wii's Virtual Console, in fact it is the second most popular purchase (behind Super Mario Bros), which is impressive since N64 games cost a fair bit more than the rest of them, but the cost isn't too bad, 1000 'Wii Points' (I think that's between 8-10 pounds, but I can't be 100% sure).
Maybe you've played the original Super Mario 64 to death, collected 120 stars numerous times and are looking for something new. Yet again Nintendo are there to help. In 2004 Nintendo released 'Super Mario 64 DS'. It's basically an enhanced version of the original game, with newer graphics and more stars (while changing some of the more horrible stars from the original). Not only this you can now play with three other characters; Luigi (who can jump higher and thus is probably the best character), Wario (who can break certain blocks other characters cannot) and Yoshi...who's practically useless.
|Comparison: DS (left) - N64 (Right)|