Damned hard choice to make....
Offhand I would say it depends if it's an IO server, and what size maps. It also depends on the number of players.
Dalian: Is VERY good if you have 20+ players, and is even excellent at up to 64 players. The small map is VERY good for IO.
Wake: Meh... I dont like it personally, but I know others do
Karkand: Not so fun as IO (unless it's small/medium), loads of fun if the server is full, NOT so fun if it isn't.
Daqing: Dont like the large versions, small map is fun though. Not very good as IO
Shonghua: Nice if you have a full server, especially the medium sized map. Not so good as IO
Zatar Wetlands: I dont think anyone likes that map.
Sharqi: IO is good. Small map is too imbalanced. Can be played with many or few people on the server for larger maps
Jalalabad + Oman: Large map is not good for IO. Normal play is decent if you have at least 50% players online.
Mashtur + Kubra + Dragon: IO is fun for small/med map. Normal play is decent if you have many players on a large map.
Fushe: Cool as small/med map, very good if you do not have a full load of players. Not so fun as IO
Clean Sweep: Not good as IO. Small map is too imbalanced. Fun starts with at least 50% player load
SF: No night maps is the norm. Though night maps can be really fun as IO. Iron gator pretty much sucks as IO on the med/large map. Other than that... I dont think there are enough SF players to justify more servers. You need a VERY dedicated player base to get it up and running.
EF/AF: Great wall is TONNES of fun as small map and IO. Though in general, a lot of the EF/AF servers are gone, so like SF, it may be tough to find a decent player base. But UNLIKE SF, you CAN put the maps in your rotation, just "bundle" them together so you have regular BF2 maps a lot, and AF/EF a bit. This way you wont loose too many players to the fact that they dont have AF/EF. Many players DO, but not all, so only pick a couple of AF/EF maps.