The main reason I loved Watchmen so much was because I knew nothing about it going in, and was therefore expecting some silly our-group-of-heroes-vs.-their-group-of-bad-guys thing, and was totally blown away by a story that was anything and everything but that.
As for Dark Knight, I found it to be ridiculously overblown and convoluted. Bale's performance was one-dimensional and shitty, Maggie Gyllenhaal is uglier than a bulldog's asshole, Ledger's Joker annoyed me, and I absolutely hated the ending. And everytime somebody tries to prop it up as the comic movie equivalent of Citizen Kane, I dislike it just a little bit more. Not only do I vastly prefer Batman Begins to Dark Knight, but I think BOTH Burton Batman movies are better. Although obviously Dark Knight is better than the other two.