linux native of course.

mine is assault cube-
am totaly obsessed with AC and love the fact its one of the few that was built on an independant engine that isnt quake IIIs.

superb graphics on the netbook x laptop of mine [a acer ferrari one] and dads nearly fossilised pc,superb addictive play,had bought a decent gaming mouse just to play this.
the bro in law was quite critical of it though saying it looks really outdated and woudnt stop whingeing about the looks,he is used to all the latest CODs and whatever-he doesnt understand that it was deliberately made to be balanced in graphics so that it coud be accessible by the majority of us whom unfortunately dont have wads of cash to buy our dream mega rigs.

another favourite of mine though not played as much is open arena-
based on the quake III engine and stays very true to it,which as a old quake III player feels awesome.

the likes of urban terror and tremulous woud be on the list if they had bots on offer,am a rubbish player due to having difficulties with processing information and tracking movement fast enough-so will never play online against others,being severely disabled find it easy enough to be insulted with 'retard' and 'gay' without having to go on a server to get it.

there are so many quality big linux games,people who say we dont have any need a pair of glasses.