I tried them all and i ended up in machinist. I had the following reasons:

I hate watching and refreshing a key buff (BLM or DRG)
Watching debuff timers were annoying in raids (SMN and BRD)
I just hated mudras (even post NIN mudra lag update)

That really leaves monk which i havent really played seriously yet. I like machinist not because its top dps but i like the style and it does not have to watch timers like a hawk.