Man, linux has all the best games. Just a few i've been digging. I'ma add more as i futz around in here.
flobopuyo - puyo puyan or whatever it's called. i love it.
cuyo - well-done crazy puyo-like thing
xscavenger - lode runner!
asciijump - wierd ass shit. i want more things like this
blast - a retarded ass-looking blast holes in desktop windows thing. essential.
sl - aims to annoy you out of sayin sl when you mean ls