I usually lean towards games being more of an experience that just a little fun time, so I find my favorite genre being RPGs. They're usually insanely long, which really helps me appreciate the 50-65$ I pour into it, and length always makes a game better because there's just more to do. It also helps with the experience in the way that you begin to appreciate the characters and battle style more as time goes on, giving you a chance to connect with them and delve deeper in the intricacies of whatever battle system may be present, along with the quirks that it brings. Speaking of battle style, that's another thing I really love about most RPGs. So many of them have seemingly simple ones, but once you spend enough time with them and get to know how the work better, then you get to see just how strategic so many of them are and how difficult it is to perfect it. Prime examples are Pokemon and FFCC: Crystal Bearers. With characters, it's a bit harder to say. It seems so many of them are cliche these days, but it doesn't change the fact that I've really enjoyed them in a few games. Good example of games where I really connected and appreciated the characters are FFX and World Ends with You.
Also, expanding on the strategic nature of so many of them. Other genres seem to specialize in actual skill. Like a platformer on your reflexives and how quick you are, or a FPS were it's how well you know your weapons and controls and how to utilize them best. With RPGs, it's usually just your mind. You don't have to press the A button at just the right time so you won't fall down a hole, and you don't have to know the specifics of your weapons during battle right down to the reload feature and if you actually have time to do so. It's more like thinking ahead, guessing your opponent's move, and attempting to pre-empt or counter it. I guess I just really like how RPGs have the ability to get deeper and deeper, while other genres establish their position and just increase difficulty.