A Sun that Never Sets is definitely my favorite Neurosis album, and also one of my favorite albums in general. I've actually been debating with my friend over which is better (along with Eye of Every Storm). Out of their older material, Souls at Zero and Through Silver in Blood are equal, and Enemy of the Sun is decent. I find Grace and Given to the Rising just "decent" as well. The first I don't like and the second only has a few good tracks. The album they did with Jarboe is okay I guess. I decided to rate all of their albums because they used to be my favorite band (not anymore but they're still up there).
Anyway, I guess I like StNS best because of it's light atmosphere compared to their others and it doesn't have that "adding a random pointless riff at the end of every song" climax that nearly every song on EoES has, which I would have chosen otherwise if it weren't for that.