A lot of folks seem to really not get enough of Dead Hills HAs right now. Must be the the upbeat music and the varied color palette used within the zone.
If I start listing them out it feels like I'm just listing all the zones I can think of. Over the years I just have too many to count.
I really miss old Freeport lots of memories there. Killing slate in commonlands yrs back made it fun being kos lol. Course back then there was no baz and you got spammed to death when you entered the zone EC tunnel 1st and 2nd torch. Andarriel
Rathe Mountains/Lake Rathetear. Just a great area all around, even if pointless to be in after reaching level 40 or so, lol.
Man, I like a ton of them, but since many have already been listed I'm going to add HHK, ToFS and OoT.
Rathe mountains drove me crazy before in game mapping existed. Trying to find something by /loc only was horrid. Another honorable mention that's a little newer - Ashengate
Resplendant Temple is pretty insane and extremely well designed. If they had a quest to be able to use a portal from ground level to the top level - it probably would be perfect.