>>314791710Monk has the highest potential DPS, but has a lot to juggle to keep it up.
Ninja has high DPS, brings some potent Debuffs and enhances their own and the tanks DPS with one. (Warrior has a similar debuff that overwrite each other.)
Dragoon is alright, but animation lock from jumps will fuck you over occasionally. They have two off GCD stuns, and bring a debuff that ups theirs, Bard's and Mechanist's dps.
Black Mage has extremely powerful multitarget capability, and respectably powerful single target capability. Sleep is about all they bring to the party for other utility, but I can't recall a strategy that really calls for it.
Bard brings alright damage, a silence, and the ability to restore party TP or MP over time, or buff mage damage.
Mechanic loses the Mage Damage buff, but gains a stun that's tied to its silence's cool down.
Summoner is all DoTs.
The tanks are all pretty similar. PLD has the most mitigation, because it's the only one with a shield. Warrior is DPS king of the tanks, so is perenially popular. DRK is popular right now, because it also manages more DPS than PLD. But they're all approximately the same in the end.
Scholar is a DPS class up til 30, (same base as summoner, arcanist) so it doesn't have much in the way of actual healing. But it does have barriers. Adloc creates a shield effect that is equal to health healed. (Doubled when it crits.) Sacred Soil reduces damage to everyone within an area. And one of the fairies summoned has a move that reduces incoming magic damage.
White Mage has the strongest heals. I think still the strongest Stoneskin, though everyone has the same Protect spell now. They do have some MP conservation issues.
Astrologian is pretty much inbetween. Once you get the abilities, it can emulate either other healer, to a mildly reduced degree. (Shield Stance doesn't double on crit, HoT Stance aren't quite as strong as WHM) It makes up for it with the randomized buffs.