RPGs are the most popular because they satisfy a large portion of gamers; I also like RPGs, but there are different types of RPGs. There are epic RPGs like Mass Effect (you have to kneel and tremble!), and to some extent, Final Fantasy. There are Diablo clones, there are action/RPGs like Oblivion and Fable, and there are cRPGs (computer RPGs), a rare and my favorite type of RPG (after all, I'm a PK player!). A prime example is The Witcher. Games of this genre are characterized by an abundance of text, menus, and a focus on PK-style controls. Since all RPGs now are either multi-platform or console games, it's a rare genre. In general, PC games are moving towards PK-style games; the top 5 games are still games from 2004: WoW, The Sims. The PC is turning into a platform for MMORPGs, although I don't think games will stop being ported to PC. But after the failure of Crysis, you can forget about PC exclusives.