Oft-hosted levels are good because both parties will likely know them, but duels on a mutually unknown level can be great too. Plus there are LOTS of great CTFs worth getting to know. I'd recommend any of shadow's, bloodbunny's, mike's, jeh's, martin's, RockyR's, ST's, onag's, or mine ;) without any hesitation.

(these are by no means the only good level designers out there, mind you! I forget way too much.)

And if you don't like semiconductor, that's fine with me... just don't bother submitting a lev to my contest! :P

(that was a joke... although it may have some relevance given that I designed the level with the same brain I will be judging the levels with. but don't let it stop you)

stripe