RAMBLE:
I love the idea with the towers. Reminds me of a UT map called something forest, where you have something like that, but in 3 dementions -- up down as well as left right.
I also love UT type of maps, for people who have played UT. I like maps that are simple, not necessarily designed to be intricate or scary. Something with lots of tactical positions, but nothing that you could get lost in when playing it for the second time. Pretty much all UT deathmatch maps are like this.
Also, I like maps that look nice, as in pleasant. Like, a place that you might go sit in when you're looking for a relaxing sit. Something outdoors-y.
IDEA:
OK, I have it. Sorry for the above think-aloud. An outdoor map with ruins, both above ground and below. There could be tonnes of hiding places, lots of stairs with platforms on which to perch/jump/shoot/set up base from. Also would be nice if you threw some trees and stuff in that you could possibly jump on, lets say, from the ruins -- hidden paths through trees. This map would combine ruined ancient civilization style building as well as nature, making for a map with great places to hide and set up cleaver bases. That would instantly be my favourite map.