I've gone back to ToFS several times in this level band and I really don't like it. Floor 1 is a boring key slog with the same few mobs everywhere. Floor 2 has a high mob density with a lot of enchanters and necromancers. As a bonus, sometimes floor 2 will charm the pet of some farming high leveler; when the high leveler gates, the pet is left behind as a much-higher-level mob to torment poor groups that go there. On top of that, XP is mediocre.

If you want to do the higher levels of ToFS later you may as well go now, I suppose. But for the most part ToFS is one of those dungeons that I want to like and don't. It would be worth doing the key grind, I think, except the ZEM is just terrible.

SolA is another good choice but people do adventure there these days. About half the time I bring people to SolA there's a group at bar and another higher level monopolizing the north part of the zone (kindle/captain/etc) for ore. That having been said, in the mid 30s you can probably get the king room and pull torturer from there. Good xp, great cash.

Like Sol A.

CT would be another option that should be rather empty.

Kaesora for sura

Live side of lower guk is never crowded, and close to evil cities

My fav mid level dungeons have always been ToFS and Cazic Thule. CT is especially good if you crawl it, don't do a static camp. Through the maze into pyramid area, down the pyramid to the lower level with water filled rooms, to the Avatar of Fear room and then back to the Court Yard. I was very upset when CT was revamped on live.

ToFS is also a lot of fun if you have a static group and go from bottom to top as you level.

CoM is a good place 40-50