It all depends on the style of play you want. Do you want up close, furious and personal? Monk or Ninja, maybe Dragoon. Do you want ease of play? Bard or Mechanist. do you want powerful rotational based abilities? Try the casters. Every DPS can be used and used well, but it's all down to what you want out of it. Personally, I use BRD, simple, straight forward but capable, but I've leveled most of them (minus mechanist) to at least 50. Gameplay does change after that though, so this may be a touch outdated. BRD I have to 60 and I've found most of the new abilities, really help to mitigate some of the stresses I felt prior during 50 and below content. Good luck!