i remain a big fan of deck16 and its associated music in all its iterations, just a great map with a mix of open and closed areas with a ton of verticality to mess with. hyperblast is a fun one too

rankin from ut2004 is also an honourable mention, and so is the music from facing worlds - but not the map itself, since it often turns into boring sniper duels or getting headshotted from a mile away which is just that fun to deal with imo

there was also a version of ctf-1on1joust for bombing run in ut2004 i played that got really stupid fun when you played that with more than the 2 players it was actually intended for