Why do you like Smash brothers?

[Smashchu2]

So I was wondering. What make's you enjoy Smash? What make's you keep playing it? What's the most importaint asspect of the game to you?

For me, it's gotta be the multiplayer. Love playing it with friends. Can't really get this excitement from other fighting games (as much as I love Tatsunoko vs Capcom).

Oh, and to make it more interesting, what would you add to Smash bros if you could?