Yeah controllers were the most powerful class in that game. Debuffs, crowd control, pets, buffs and heals, and to some extent DPS as well if they were fire/kinetics. By MMORPG standards, it was quite a powerful class indeed.
DC Universe Online had Buffing/Debuffing as one of the 4 main class types, along with the 3 others mentioned in TC's first post.
In that game, they're called "(Con)Trollers".
If I remember right, this class was usually the most in demand for teams, raids, etc. Of course, it's mostly because most people want to be DPS (as all players can choose to be DPS whenever), while just one the three other classes are the alternative choice. Tanks aren't really that necessary most of the time, so you end up having a shortage of Healers and Controllers as a result.
Like, this is true and all, but TC cares about PvP it seems.
How did you get that out of the OP when it mentioned Final Fantasy XI and Rift in conjunction with dungeons?
You don't need ECM in PvE because just loading up on the damage, having the right tank, and aggro control lets you do just fine.
Not only that ECM screws up enemy locks making it easier and more likely for them to either target the ship(s) you don't want them shooting at or your drones. As I said, painters are pretty much the only choice for PvE EW, and that's really only because they take the place of (omnidirectional) tracking computers/enhancers for both yourself and everyone else and signal enhancers and sensor boosters for everyone else.
"Before I send them to hell, I shall let them see heaven." - Claptonvaughn, http://www.gamefaqs.com/boards/605432-path-of-exile/68145584#11
Everquest 2 had a lot of debuffing. But of course for it to matter nowadays youll have to get max level and prolly raid and do high end dungeons. At lower levels stuff dies so fast debuffing hardly matters.