You can use the simple server browser by checking the "Simple server browser" option in the bottom left hand corner. This is kind of broken for me right now, however:
You can also use the full server browser and filter by map. This is generally more reliable, but you need to know the full map name (e.g. cp_fastlane
; just "fastlane" won't do):
Most servers, however, rotate through multiple maps. This is perfectly fine and a good thing. Servers that play the same map 24/7 are more likely to have bots to help people who want a game on that map regardless of time and map, and are more likely to be part of a larger server farm that makes one such server for pretty much every single map out there. Those are hardly conducive to community building.
With no community, you don't have regulars. With no regulars, you don't have donators. Without donators, you don't get money to help offset your hosting costs.
To contradict with the above, however, if you really do positively need to play on a map and there's no such server out there... you can start your own! It isn't rocket science. From the main menu click on the '+' button, pick 'cp_fastlane' or whatever as your map, tweak the settings in the Game map if you need to, make sure you have proper port forwarding in place so people can connect to your server if you're behind a router and - hey presto! You're playing on Fastlane and now you just need... others to join you. Invite your friends or something. :)
Best Answer
The only other method I know of is to get one of the new crates. However, Valve did something different with crates this year: Instead of the crates being free and the keys costing money, instead the Unlocked Creepy Crates cost money and don't require a key.
There are 9 Unlocked Creepy Crates, one per class.
Tradeability
On a side note, Halloween items aren't part of the normal drop system, so you can't get one as a regular hat drop.