I like Crystal Tower, though last week with LoTA I had to teach 9 people how to do it and it was a gong show.
I'm not even joking either, 9 people got the LoTA achievement when we completed. They'd also start the fights before I could finish explaining the mechanics nearly causing us to wipe a few times. (The pad section for example, two teams had only 5 players in them so the tank had to kill the mob)

But I still like the raids, the locations are beautiful and the fights are interesting.