Here is a list for the OP:
- Low Level Roulette (Daily Bonus)
- Guildhest Roulette (Daily Bonus)
NOTE: They made an adjustment to were every class you level now gets the bonus EXP for first time completion of a guildhest.- Leves (6 per day)
- Beast Tribe Dailies (6 per day)
- Hunting Log (Once per 10 levels)
- Challenge Log (Weekly)
NOTE: Bonuses for doing Dungeons, Fates, Guildhests, and Leaving Commendations- Fates (Repeatable)
NOTE: As someone mentioned most can be solo'd, if its a boss fate spec your chocobo to compliment your class. I was farming fates last night as a Bard in Costa Del Sol with no one around, only fate I cant do "It's Not Lupus".- Dungeons (Repeatable)
NOTE: Use Party Finder to find people looking to grind dungeons, select all languages in Duty Finder, select Join in progress as well
Some extra info:
Bonus EXP: There is a 50% bonus on all EXP but Quest Completion EXP once you get a single class level 50. There is food you can eat to get bonus to EXP. There are manuals you can use to give bonus EXP from the GC. Make sure you log out in a sanctuary so you can get the Rested EXP bonus every day. If you are in an FC ask if they can put up the "Heat of Battle" buff to get extra EXP as well. Ventures can be obtained through grand company seals. Turn In any green/pink items you don't need to the GC and get seals, do fates to get more seals, also there is an FC buff that nets you extra seals at turn in.
I have leveled all my DoW and DoM classes to Level 50 except Bard which i am currently working on and sit at lvl 35. I still have side quests left in Corethas. While side quests help, they are not very worth while because they do not benefit from the EXP bonuses mentioned above. Honestly the above content gives you a couple hours of play time a day (casual players) or gives you the ability to grind levels almost as fast as you want (hardcore). Like someone mentioned if they put in enough side quests to level every alt class to 50, the game would be loaded with pointless quests that eventually seem more mundane than everything else.
There is a lot of content you just have to know where to look. Also, ignoring "End Game Content" might be your problem as well. Getting a class to level 50 is really only the first 25% or less of the game for any given class. The real meat and potatoes of this game is meant for level 50 characters. Just so you know, the only end game content right now is Second Coil, everything else is spamable and used to go from lvl 50 (ilvl 50) to ilvl100/110. Heck you don't even need to do Second Coil to get to ilvl 110.