[trover4]

Are we looking for high quality custom maps (as in looks) or proven fun custom maps with no regard to aesthetics?

good customs:

ctf_mach4 (small map, good firefights, can lead to engi turtling though)
cp_broma
cp_frieght
ctf_convoy
cyberpunk (deathmatch style map but it has alot of attention to detail in the map itself)
arena_lighthouse_b2 (played this on 2f2f, was actually a well put together arena map)

There are plenty of good custom maps.

save cyberpunk...i would definatly be down if it were just these, but the reason people don't play custom maps seriously is because you can't play mario kart seriously, plus its an extremely lame map regardless. i would vote

ctf_mach4
ctf_convoy (not that great, but if played seriously, is a lot of fun)
cp_broma
cp_station (if you add station i am 100% down for playing)
cp_freight
and of course
pl_hoodoo