Strong duo synergies?

[sarehptar]

Ditto to pretty much all of the above--if you want to roll a healer, bard will be your DPS best friend--scholar doesn't rely on mana song as much, but the bard can switch between ballad and requiem to boost scholar's mana and DPS damage in the same fight. (Foe's Requiem doesn't just boost elemental attacks, so it can and should be used for summoners/DPSing scholars.)

Although I don't recommend picking two DPS classes at once, I'm surprised bard and dragoon got overlooked as a pair. Dragoons can buff bard damage which helps to mitigate the negative effect of TP song, they can handle the stuns that bards can't, and provide strong single target DPS as well as AOEs in desperate situations. Typically the easiest four-man runs I get are bard/dragoon DPS combos. Dragoon and bard are also both pretty good classes for PvP.

Ultimately, since you can be any class you want at pretty much any time in this game, you can basically pick whatever you want now and then just change your minds later if you feel like it's too slow leveling or the class/job is boring. Try a little bit of everything and find the roles you like best.