I really have a hard time picking!
I like Taris because of the aesthetics and layout, the people, and the multiple levels.
I like Dantooine because it's gorgeous, and the atmosphere is calming, and I like the feel of history to it, given that my companions Bastila and Juhani have been living there
and I, Revan, had trained there as well.
I like the people, I like the enclave, and I like the tension surrounding the isolation and practices of the Jedi there. It's homey with just the right touch of eeriness.
I also love Korriban (the aesthetics, the Sith presence, the more serious atmosphere) and Lehon, which was absolutely stunning, creepy as hell, and gave me all the feels.