A multilevel arena. The textures keep you from getting your bearings for a little while... and your opponents will keep you from it for as long as you play. Very open, with lots of ways to get from point a to point b. Always check above you...
A small, tall room with stairs around the outside, a couple of protected rooms with big weapons (and teleporters as the only entrance), and sniper pillars. Vertical distance is big enough that you actually have to aim.
A two player map. Each player is in an enclosed space, facing the other across a no-mans land. Death rates will be low, unless your opponent doesn't know how to take cover.
Huge. Lots of square rooms, with floating stones i the center, and sewage pits filled with drones, linked by sewage passageways. Some cool effects, but no plot to speak of (well, stay alive long enough to see the whole thing...).
A circular main arena, with a passageway circling it at ground level, and another on the second floor. Sniper ledges with lots of cover are also on the second floor. There are two additional versions of the map included, for smaller groups-one removes the ground floor outer passage, and one removes the second floor outer passage.
A straightforward carnage arena. Two pillars in the center, a sewage-filled passageway around the outside, and some outside ledges. There seem to be some bad walls (poly edges with actual textures assigned, even though it's supposed to be open space), but I didn't get any crashes because of it...