Quote from Cucurbita;180860:
Just don't do the low growth rate characters.
Stick to adventure or cygnus knights for steady leveling.
Supposedly, with the Big Bang patch comes a level cap removal on all non-competitive (the Carnival Party Quests) PQs, so leveling shouldn't be much of a problem if the exp rewards from them are scaled for your level, so that the Fourth Jobbers can party with lower levels, and have incentive to do so and not let the lower level leech off his higher level friends.
As for the sticking to Adventurer or Cygnus Knight advice, from what I've seen, Mechs (the pirate class of the Resistance sub category) looks pretty hax, but until I learn Korean, I'm just going by the wiki I use for Maple, and they have nothing on Mechs yet, so I can't really see what their skills do outside of videos.
Battle Mages (Resistance Mage) look like a slightly more offensive version of Clerics. They have buffs that increase damage the party does by a percentage (Dark), increases the party's movement and attack speed (Yellow), and one that looks bad at first by distributing damage dealt to a party member/Battle Mage (Blue, and I'm not sure who's affected by the recieving end), but the later jobs have skills that buff these buffs. 3rd job has a passive that boosts the Blue Aura's buff by increasing the amount of damage distributed to the party, but grants the party a 60% Defense boost, so it pays off in the end, and an active skill that buffs the current buff's abilities. 4th Job has boosts for both the Dark Aura (up to +20% damage dealt and deals chip damage over time to enemies inside the area) and Yellow Aura (up to +40 speed and increases the party's attack speed by 3 (meaning practically every weapon rates at a Faster speed or higher) and lowers any enemy in the area a -30 speed debuff).
Wild Hunters (Resistance Archer) are pretty sick too. In the first job they get a mount skill that they can increase. At the highest level of the Jaguar Riding skill, they get a 40% HP boost, a Critical Hit chance of 40%, 60 Speed (meaning that only other characters on mounts can keep up with them, and Wild Hunters can fight while mounted while everyone else can't) and a 150 Avoid (meaning that they won't be hit by weaker enemies much). They get a double jump, so they can move much further, and they have Triple Shot (Double Shot does 2 hits at 130% of your normal hits, Triple Shot does 3 hits at 90% of your normal hits, and like Double Shot, each hit can crit, so it will do some nasty damage).
Second job is pretty standard archer (Crossbow Mastery, Soul Arrow, mob skill). The Wild Hunter's Mob skill is a combination of the Ranger and the Crossbowman's Mob skill (piercing attack that can stun). If you choose to be a rider, then you can raise a mob skill that can stun, and an attack that pretty much turns your Jaguar into Kirby by swallowing your enemies to either use as ammo (800% attack) or to keep as a self buff. And then there's the Mine skill that lets you drop pretty damaging land mines for a long period of time (100 second duration and 280% attack at level 20).
3rd Job is meh for the Archer, but pretty nice for Riders. Riding Mastery boosts your speed from 160 to 170, an extra 20 Avoid, and a 40% boost to all Jaguar attacks. The Archer gets an upgrade for Triple Shot in Five Shot (5 hits at 140%), Blind (self buff that causes arrows to have a 30% chance to reduce enemies accuracy by 20% for 10 seconds), and Trap (Puppet that deals damage). Riders get Crossroads (a weaker, but more likely to stun Jaguar's Roar) and Claw Cut (hits 3 enemies 4 times at 80% damage).
4th Job focuses more on the Archer side. Crossbow Expert is the standard Archer 4th Job that gives 90% mastery. Flash Rain is pretty intense in where it releases a bunch of arrows that explode for 1200% damage each. Nerve Gas is a Taunt, except instead of buffing one monster's Defense for more Exp, it causes 6 monsters to give more Exp and doesn't buff the monsters. The Archer also has Hurricane, just with a different name. Riders only get a greatly upgraded Jaguar's Roar with Sonic Boom (620% damage and 100% stun for 12 seconds) and the buff Beast's Anger (an extra 30% attack, 80% HP, 30 Speed that lasts for 90 seconds). Only problem with Wild Hunters is that you can't use your archery skills while on a Jaguar, and obviously you can't use your Jaguar skills while you're unmounted.
I'd recommend Cygnus Knight only for people that are bored with their other real characters. Unless Big Bang also removes the 120 cap for Cygnus Knights, and a player should be able to get to 58 relatively quickly with the new exp curve, then the Cygnus Knight is really practically over by the time the grind really hits.