RPGs, Visual Novels, and completely mindless, plot-light Action games. Although I can't stand Action games that have loads of button mashing or an angry protagonist God of War.
Mostly RPGs, adventures and Strategies.
-----------------------------------------------
And You can't actually add Visual Novels to the list, because they're not Genres.
Visual novels is a media, much like a novel, a movie or even a game itself.
I had to go RPGs because of the Elder Scrolls series, and Fallout series; along with Dark Souls (well made but fuckin' hard), Borderlands, WoW (I use to play it quite a bit), Deus Ex (newer one) and others that make the genre great. Of course I'm not including many of the original hardcore RPGs, but at least I like RPGs.
I have to go for RPG's well JRPG's to be accurate. Nearly every JRPG always make me waste so much time on it, something about the good game play and story mostly keep me going back for more.