Well I mean avg..i can run Perfect World..
http://www.addictinggames.com/index.html
or try 2Moons,DOMO,Mabinog, or go way back and play Tibia. Right now on my computer I have..Latale,4story,sugarrush,PSOBB,Dreamlords,Req uiem,WOKF,Wakfu,Trickster Online,Anarchy,Savage 2,Holic,Combat Arms,ROE,Archlord,PW, and a few offline games...Hmm..Maybe I should delete a few games..Not playing all of them..
Mabinogi in my opinion
Oh yes, I'm so glad Turf Battles is coming back. That game was too fun.
As for low spec games.. any 2D MMO I suppose? Or I guess you could try that Regnum Online since it has that whole "huge" expansion now. I think I read that Shaiya wasn't too demanding either, I'm not sure though.
i say mabi its really addicting i just got rank1 lightning i owend my friend without turning into DK My ego is soo cool ^^