If you want to find parties fast, then you have to play either as healer or as tank. So scholar, white mage/conjurer, warrior/marauder or paladin/gladiator.

But personally I wouldn't worry too much about that and just play the job you enjoy most. Arcanist is probably the most played class at the moment, yet I always managed to find a party with it regardless. Sure, it may take longer, but you can always do quests and whatnot while waiting for the duty finder to match you up.