I am a fan of Nintendo and I have only ever had Nintendo consoles. So I choose SSBB, I have played Halo but I didn't like it much. SSBB has tonnes of new content where as Halo 3 I hear is worse than Halo 2. SSBB is a fun game that never gets boring where as Halo you are stuck doing the same things over and over again, where as on SSBB you can do Subspace Emmissary or play with friends and do events, or work on getting stickers/trophies/achievements.
SSBB. Halo 3 was awesome, but it felt like more of the same. SSBB on the other hand has done the impossible and bested melee with tighter controls, better visuals, and more modes. Not to mention Subspace Emissary mode. This game is just too huge not to be the best of the best.
Halo 3 I'm afraid. I'm a nintendo boy through and through but I just don't like the way that the controls for SSB have been translated onto the Wii. SSBM on the Gamecube anyday!
it depends, if u have a bunch of friends over then SSBB but if its jus u or 1 other person or if u have live then Halo 3. i personally like halo 3 cuz i own at it