There are many: World of Warcraft, star wars, everquest, star trek, mass effect, torch light, final fantasy, dragon age, fallout, diablo, guild wars, risen, jade empire, titan quest, deus ex.
There are many, including most mmo games such as World of Warcraft, everquest and FFXI. You can also try single player rpgs such as Kotor and Assasin's Creed.
There are a number of options for RPGs on the computer, there are also MMORPG that allow you to play with other individuals online. For standard RPGs there is Dungeon Siege, Diablo, Neverwinter Nights, etc. For MMORPG there is World of Warcraft, Dark Ages of Camelot, Star Wars, etc. These are just a few, there are hundreds of other titles.
