Be ready to have your heartrate rising.
alltalk, eu, fastdl, fnaf, freddy, friendlyfire, glub, glubbable, halloween, increased_maxplayers, norespawntime, respawntimes, s, scary, sf2
Random server mode
This will pick any community gamemode (hence not official gamemode's), and choose a random server from that list with at least 5 players in it. This is the best way to get in touch with the funkiest maps/gamemodes/people!