RIFT from day one. Or perhaps you eschewed it due to the slow rate of rewards and the awkwardness of needing PvP souls to make any real headway. The good news is that the game's upcoming patch 1.7 is taking aim at a variety of PvP issues, starting with a change to the Prestige Rank system. The new system will offer 40 ranks instead of the previous eight; while the time to reach the cap will remain identical, you'll gain new ranks and rewards more frequently, making the overall experience smoother.
PvP souls are being outright abolished, with the abilities rolling into the new Attunement Path of War that works just like other Planar Attunements. There's also the addition of the "mercenary" option for queueing, allowing players to fight with the other faction during PvP matches in order to ensure a balanced and full group. All of this combines with across-the-board item improvements to ensure that following the patch release, taking part in PvP should be quite a bit more fun.