Games/FPS

Urban Terror (urbanterror)
Urban Terror is is a free multiplayer first person shooter based on the ioquake3 engine. It can be described as a hollywood tactical shooter; somewhat realism based, but the motto is "fun over realism". This results in a very unique, enjoyable and addictive game which reminds of Counter Strike, but is more action and speed oriented.

YouTube demo

Warsow
A fast paced open-source multiplayer shooter based on the QFusion engine. It is similar to Quake3, but is set in a futuristic cartoonish world. Warsow is all about speed and movement and features known game types like capture the flag or instagib.

YouTube demo