With so many genres of video games out there and the potential for totally new genres to be created, an avid gamer is likely to develop a personal favorite based on what he/she grew up playing or their interests. Personally, I'd have to say that offline RPGs are my favorite genre by far. Specifically, Japanese RPGs.
The Japanese have always been excellent story tellers (which is why so many people are wrapped up in japanese anime) and their game plots are just on a whole different level compared to the plots found in American-made RPGs. This isn't to say that American games aren't good, but what American developers tend to be more proficient in is shooters and sports, two genres that Japanese developers couldn't compete in.
Growing up the youngest of three brothers, I would always watch my brothers play video games like donkey kong and super mario, and I would pretty much only play a game because they were playing it, it looked fun, and I wanted to do stuff with them.
But the moment I first played a Japanese RPG I was hooked. Of course, the game that got me hooked was the legendary Final Fantasy VII (BEST GAME EVER!!), although I recognize that after the 8th game it just went downhill from there. But we played that game for hours and since I was young and inexperienced, I was naturally horrible and could never get past any boss battle without the assistance of my older brothers.
Sadly, I never beat that game and that is the one regret I have had in my life since I've been searching for years for another copy and have never been able to find one that wasn't so damaged that it was only playable up to a certain point. This and a few other games like FFVIII (which I also never beat *sigh*) and The Legend of Zelda: Ocarina of Time reinforced my newfound love of Japanese RPGs.
So that's my view on the Genres. But what does everyone else like?
Well according to a survey conducted by the NPD Group/Retail Tracking Service, the top 3 genres sold in the US in 2010 were Action, Sports, and Shooter games with 21.7, 16.3, and 15.9% of sales, consecutively. The other 11 genres listed each only had less than 10%. Action games? Come on. Really? The only action games I've ever REALLY been into were Banjo Kazooie, Conker's Bad Fur Day, and Psychonauts, but all of those games can be considered Action RPGs. Sports games, yeah despite the fact that they're all just recycled and refurbished copies of the original with slightly different controls and stats, I enjoy them when playing with friends. For a while. After 4 games, it's time to find something else to do.
What I'm really surprised to find is that shooter games aren't the top selling genre, especially considering ground-breaking franchises like Halo and Call of Duty, and now Battlefield. You know Call of Duty was all the douche bags in high school talked about for a while and I couldn't blame them because I was just as addicted. I was just in the closet still with my love for the game. Dead Space is awesome because it mixes the excitement of a shooter with the adrenaline-pumping thrill of a good horrow, and Battlefield 3? OMG best online multiplayer I've ever played in a shooter. But still, nothing has my heart like a well-written, well-developed and designed RPG.
After all, who wants to be crushing skulls in an Abrams Tank when they could be riding around on a giant chicken?