http://projectmgame.com/en/I've recently installed this SSB mod and been enjoying it a lot. It rebalances a lot of the characters, changes a lot of moves, adds mewtwo, adds roy. It separates the pokemon out, and gives them new down-specials. Lucario doesn't have that silly mechanic where he's rewarded for being bad. Pit doesn't have that terrible side-special.
Also, the game physics are more melee-like, so characters are less floaty and fighting is slightly more combo-oriented. Some old stages make a comeback, and some of the new ones got reworked to be less awful. Also, new music! ROB has a Virtual Boy skin! Giga Bowser!
You just need an SD card that's between 512Mb and 2Gb to install it. Walgreens sells 2Gb cards in the states.
And a trailer.