Mine used to be Canyon (for the cannons), LightPassage, or Towers or Prison (because I'm sentimental and those were two of the first maps in the server). Now it's CTF-Corridors. The pistol kills I can get there are fantastic
Evil: I'm a man who likes a challenge.
BlackOut: See 'Evil' and 'CTF-Corridors.'
Any map with the 'Lava Surge' mechanic.
CTF-Waterfalls: Scenery Porn.
CTF- Corridors: Unlike a lot of people, I particularly enjoy mazes. Especially when players are blasting at you left and right.
A few more.
Spherical(And its miniturized version)
Anubis(Dem cannons)
CTF-Cliffs.(I don't know why, but it's one of the few CTF that I love)
CTF-Waterfalls.(Rockets.)