Try Rift or Star Trek online.
In Rift there are several Talent trees availible so for example every class can fill a role.
Rogue- You can be Melle DPS, Ranged DPS, Pet DPS, or play music or support your group as a Bard or Technician.
Warrior- Melle DPS, Ranged DPS, Elemental DPS, Pet DPS/Support.
Mage- Several Pets (Necromancer, Elementals and so forth) At higher lvls you can become a Lich. Or a Fire Mage, Or some kind of Stormbringer or even best of all a Melle Mage and hit stuff. Want DoTs? Their is a complete Talent tree dedicated for DOTs, want to play CC, Theres a spec for that. Want to heal your group while Nuking things? Also possible with the
Cleric- Want to Heal? or Maybe play as a Disc Priest with hundreds of Bubbles? Or some kind of Strange Fire mage that heals wounds with Fire and burn your enemies? Or how about Melle DPS, who can shoot lightning. What about as a Pet class and letting Fairies kill your enemies? Or best of all making some Kind of Ranged Paladin throwing around Bolts of Judgement or Bolt of Retribution.
http://www.rifthead.com/stc
Or try Star Trek Online. You can fly, equip your own Spaceship or just walk around with your Officers and beat stuff up as a Gorn. Or some kind be a Vulcan or a Romulan. Why anybody wants to be anything other then a Gorn I will never understand.
In my experience both games are free and you really do not need to spend a cent to enjoy the content. In Rift bonus experience at higher levels helps, but thats about it.