As I write more and more, I finally noticed that I have a preference for a few related genres.
I like writing horror/weird fiction and fantasy, and I like throwing in mystery elements. When I'm working on a horror piece I find myself spending more time at the keyboard, happily typing away, with my imagination in overdrive. The enthusiasm makes for a FAR better story than something I have to kick myself along on.
I've tried humor, and while I can do a passable job my heart just isn't in it. I'll throw some humor for comic relief into other works but I can't sustain enough enthusiasm to go much past about 1500 words. Weird.
Pure mysteries don't really excite me, either. I've made a few abortive attempts to write a mystery but it goes nowhere and dies a quiet death in some lost corner of my hard drive. Sigh.
I can't write romance worth a darn. I'e tried and tried, but I end up with the most florid drivel that I can imagine. Re-reading it makes me faintly ill. I'll leave it to someone else!
I know people that can sit down and pound out thousands of words in almost any genre, and do an acceptable job. I envy those people! If I don't feel a spark when I'm writing I know I'll never be able to keep up the pace on the story and it's time to let go and move on.
I haven't tried paranormal fiction, which I have a novella idea for, or steampunk.. alothugh I do have a steampunk/horror series in mind. Maybe one of those will light a fire in me!
Random observation: writing is like running a marathon. You have to have the stamina and patiance to pace yourself and maintain progress without burning out, or you'll neever finish.