Far, far too many to list I'm afraid as there is just so many tracks I love from 1.0, ARR, HW, SB and SHB's soundtracks. But probably my favourite still is the very underappreciated Uematsu theme Piece of Mind from FFXIV 1.0's OST (not the vath theme with the same name from HW's OST). So sad and melancholy but oh so good, I still get tears in my eyes every time I hear it.