The games we are looking at here are PERCUSSION rythm games, and not rythm games in general. That is, games in which your controller is a drum(s) or set of maracas and not a dance pad or mic. My vote has to go to Donkey Konga. Reasons:
Better control (you can lightly tap the drum and it registers, in Taiko you have to whack it really hard.)
More and better songs (Konga = 88, Taiko = 31. Remixed Mario and Zelda themes barely beat out Katamari on the Rocks and Taiko March (w/ Sky Kid theme.))
Sorry Dreamcast fans, but I haven't played Samba, so I can't comment on that.