fy_iceworld
http://www.fpsbanana.com/maps/47448
This is a remake of the classic CounterStrike map, fy_iceworld. It's a very small, very simple deathmatch map. You get into the action very quickly, making it a pretty fun map.
dm_fightyard_beta1
http://www.fpsbanana.com/maps/40303
Here's another similar map. A small deathmatch map design to get you right into the action.
Fightyard beta1
http://www.fpsbanana.com/maps/120506
The same map as above, but modified for a king of the hill objective