Judging by EP, apparently literary superhero stories count as SF, so for those of you left in the cold by the abrupt ending of Dr. Horrible, I highly recommend Soon I Will Be Invincible, by Austin Grossman. It's a fun novel, and it does some interesting exploration of the possible motivations behind the tropes of superhero comics, espescially the personalities and hang-ups of supervillains. It's heavily character driven, but not at the expense of plot, and the world is beautifully fleshed out and feels way bigger than the events of the novel alone.