Haven't played all of those, but Castle3 is excellent, despite being friggin HUGE! Great visuals. Labor is also quite awesome.
I must add that ctf_badlands_classic_b3e is a GREAT remake of a classic TFC map. Unfortunately not many servers are running it, and it's hard to find a populated game.
I really want a Rock2 remake, as do a majority of others. If you are not familiar, Rock2 is one of the best CTF maps in ANY game. It had a nice twist in that you had to bring a keycard into the enemy base, and when you brought it to the capture point it would seal you in this safe room and release poisonous gas outside, killing all of the enemies who failed to dive into the water or find a protective suit. From what I remember there were a very limited amount of protection suits, so quite often you would see the whole entire team desperately trying to grab one before dying.
I know of at least two planned TF2 versions, but who knows when those will come out.