GTA has downloadable add-on content. So does Midnight Club. But no game with monthly subscriptions. Everyone would love to have World of Warcraft, but if you take a look at many of the other attempts they have largely failed. (Final Fantasy online, EA's Sims online, EA's Motor City online, Tabula Rasa, etc.) Everquest and Asheron's call were hits way back when but I think they've mostly died in view WoW.
I think the only new entry that has a decent shot at success will be the new Star Wars game from EA . . . but that is only because they have a MASSIVELY popular license (Star Wars) and a very talented studio working on it (Bioware).