I've been playing games for over 25 years and this is the best game I've ever played. Got a Wii? Buy it! :-)
Anyway, so you wait seemingly forever (17 years) for a game to come along that allows you to play with Mario and Sonic at the same time, and then two come along in the same year! While the Olympic Games title featuring the two icons was a decent enough game, Super Smash Bros. Brawl is in a class all of its own.
Since buying it I have so far played it for more than 350 hours, and I have yet to grow bored of even one aspect of it. Every time you play this game it offers something different, with so many characters, stages, arenas, weapons, challenges, unlockables, single-player, two-player and multi-player modes, etc., etc., etc. It seems entirely possible that this might be the first game in history to have infinite replay value!
I have nothing bad to say about this game, it is perfect in every respect. I'm going back to playing it now. Really, nuff said!