Well, what I like most is the combination of dark and high fantasy. If you are familiar with Sapkwoski and his Witcher, you might get a fair idea of what I like (Dragon age could be also used as an example). But I enjoy pretty much any kind of fantasy.
About sci-fi, I like it too, but I was never really good at making up all that technobabble that stands for science in science fiction. I like Star Wars or Warhammer kind of sci-fi.