Favorite(s):
Antitower because it's just so....calm. Though Calcabrina is still not something I wanna see before I log off for sleep. Also, being a FFIX fan, it's a nice callback to Ispen's Castle. Plus, still not over that David Bowie reference even after all this time.
Allagan Disco Facility- I mean, Aetherochemical Research Facility and Fractal Continuum, because Allagan. Allagan everything!
Lost City HM
Gubal Library, NM is the only one I've ran so far since I'm taking my time to get used to swapping main jobs and learning rotations. Though HM might be up there as well just from what I've seen.

Least Favorite(s):
Saint Mocianne's, though I deal with it because it's pretty. I may not like it overall, but it's pretty.
Vault, especially if you get those types who just refuse to move apart (or move at all) for the fire chains. Which I tend to run into quite often.