I'd say nay to battle - its REALLY outdated now, and really never was that good to begin with. Battle2 would be good though.
Midnight, Hellsurv, pforest, sphouse_qw are definites
Depends on what you mean by best. If you allow simple small maps that arent good for matching at all, but that still can be fun to play on a public server, then pbcup, sandtrap should be included too.
Some other maps that people havent mentioned that i will toss up:
Thunder, Brainstorm - for the larger sized maps.
warzone2 - very fun map
castle1 - a fav
just about any map shreds made
lostpath, hunt, cfire, ksplat2 - these used to be pretty popular but no one plays them anymore?
how about some of those seige or 4 team maps? I always enjoyed those.