OH MY GOD!
I love Samba De Amigo, I think its brilliant, one of the only Dreamcast games I actually played more then anything. I just think its fun, ridiculously hard to get the hang of, but when you do, its brilliant.
Another fun alternative is getting Sega Superstars on the PS2, with the eyetoy, with that you can play Samba and with the Eyetoy play it as if you had the Maracas to play the game. Its brilliant.