Hrm, I dunno about worst. Worst is very relative. But I'll give a list of what is getting popular in modern DMM by class.

In Meta/Rising:

Soldier
Heavy Armor
Healer
Pirate
Necromancer
Onmyouji
Dragon Rider
Bishop
Rearguard Tactician
Vanguard Tactician
Warrior Priest
Majin
Angel

Out of Meta/Falling:
Monk
Rogue
Witch
Mage
Summoner
Bow Rider
Pegasus Knight
Ninja
Samurai

Just a generalization based on what I use and see other people use, and what is rising in popularity. I am counting the class as a whole unless there is only one unit in the class(obviously), so I'll say monk is out of meta even if Alice is an absolute powerhouse of a unit because she's so pumped up compared to other monks.

If I didn't list a class it's probably somewhere in the middle. Other reasons would be it's hyper specialist, or doesn't have an AW yet.

Also, just an opinion, don't crucify me.