Depending on my mood to play.
I think this is a really hard choice. specially since we are talking about some different types of servers.
De_dust2 - is the most publicly played map in Counter-strike: Source. This is largely due to the fact that each team seems to have equal opportunity and the map seems to be balanced fairly well. witch makes it a really nice map.
Italy - cs_italy is a hostage rescue map, giving in my opinion a tremendous advantage on t.side. (if teams are balanced). so you have a great challenge wen playing on ct side trying to make your way to the hostages.
High School - (in my opinion i don't like it, maybe 5 vs 5 would make it interesting but so far my experience was a bunch of players camping behind bushes and pretty much every other single place don't really make my day)
Office - really nice map in my opinion , balanced / tactical map.
Cs_office is a hostage rescue map, where the terrorists start off in an office building with the hostages, and the counter-terrorists have to assault the building. This map doesn't lend itself well to camping, and at the end of a round, both teams will be all over the place witch makes it a really nice map in my opinion.
Jail - fun loll if played correctly.
D2 Death match - skill, fun map. same thing as posted on Dust 2 above with the "bonus" (no waiting time to respawn)
Anyways this is only my opinion, cant really tribute a value to any but i voted d2 death match :thumbup: