UA warriors look good since most of them would use soul drive drive as a AOE all the way till 120 and maybe even past that, although with the new patch i'm not too familiar with whether or not it would still apply since i don't main a warrior. and a UA cleric would be good, since it would be really nice to have that extra attack on him. bowman hands down don't need to be a UA and i'm not too sure on pirates.
You get the bonus +24 ATK/M.ATK from having a level 120 Cygnus on the same server. You also get a nice set of equips.
Once you get to 120 on your Cygnus, you do have a couple of annoying quests. You have to kill both a Manon and a Griffey, then you have to collect 10 Peridots from Harps/Blood Harps. Their drop rate is as low as getting 10 of any specific equipment, so be prepared to buy a 2x drop coupon (ideally during a 2x exp./drop event) to keep your sanity. It wouldn't be so bad if you were getting exp., but since you're level 120, you don't level up any more.
Incidentally, this is also the quest for getting the UA skill on any normal character, except you have to collect 10 Peridots for EACH of the 5 levels of the skill. X_X
A lot of people say that Brawler UAs are very good. Also, any warrior.
The Dufrains are missing, who can play MapleStory at a time like this?