I would have to agree that Costa del Sol and the Titan BGM are two good ones.
I don't know why some of you started mentioning FFXI tracks, but I was recently thinking about FFXIV's soundtrack as a whole (especially compared to FFXI). I think the real problem is that FFXIV's tracks don't really represent the mood of the area or battle as well as in FFXI or other Final Fantasy titles. They sometimes seem a little randomly selected.
The reason Final Fantasy songs are so memorable is not only because they're well composed but because they're often intelligently placed to convey just the right mood/theme of a specific area or scenario.
I've always liked the Promyvion music of Final Fantasy XI (I recently realized the Mizuta re-recorded it with his band at some point
https://www.youtube.com/watch?v=srpM58IsBYE). But when I think about it, I'm not sure if it's as much about the quality of the song as it is about the brilliant placement of the song considering the area and what your party had to go through. I'm repeating myself here but I think Soken's tracks are decent but they definitely don't convey the right mood 99% of the time.
Edited, Mar 13th 2014 10:20am by LucasNox