DCUO did 4 roles pretty well.

Healer, DPS, Tank, Controller. The fourth role did crowd control and had an ability to "pump out" power regen to other roles. Basically it was a job that did refresh/regain. The job also did things like DOT's, Stuns, group shields, as well as a decent amount of damage.

Then again every Job (Power) had two roles... Healer/Tank/Controller or DPS.