Batman, no question about it. I find the character fascinating and never get tired of reading Batman comics. No other comic character comes close for me.
This. I'm not a massive fan of comics and superheroes but Batman is the big exception - both as a kid and now, I think the character is great, and I'm always interested to read new stories and watch new films.
I like Batman but surprised how popular he is over Superman. I guess "The Dark Knight" interpretation has to do with it over the campy version years earlier.
Certainly that's part of it, especially as recent attempts to bring Superman to cinema have been, imho, terrible. But to me, Superman is a really dull character because he is just way too invincible to be interesting. Although he is often mentioned in the same breath as Batman I see little equivalence between the two. Batman is stretching the imagination but is ultimately just a guy in a suit with a lot of money. In theory at least, a street mugger who got lucky could take him down. But Superman makes Jesus Christ look like a Hogwarts first year when it comes to powers. The difficulty of writing stories for a character who has so many powers is, I think, part of what makes his films so reliant on either kryptonite or equally super-powered bad guys.