In general, DC films all comand a respectable grossing - Batman & Robin beat Daredevil in takings, when it was a much worse film - but their lack of production and franchise creation has been their loss at Marvel's gain. The Spider-Man movies, love 'em or hate 'em (and I know where you fall on that line, Des!), round out the top 3 whilst the latter X-Men films also took in more than $2 million domestically. With the Top 10 breaking down as 5 Marvel films, 3 DC and 2 others, I'm not quite sure what you mean when you say DC makes more moolah.
That was poorly put and rushed because I"m at work not trying to get caught talking about comic book movies online but what I meant was that recently Marvel is pumping out the films at an alarming rate but when DC does release one, it is generally a big film whereas Marvel seems content with Ghost Rider, Daredevil and the FF movies which are piss poor in quality even though they look shiny.
Not saying that Superman Returns was great, because it wasn't, but for all intents and purposes it was still an amazing popcorn movie if you weren't a fanboy and a box office powerhouse.
The Spider-Man comment: I'm getting this a lot these days...SM 3 was utter shite tossed from a monkey cage by an overrated director who had little to no care for how the characters were portrayed in the biggest waste of movie budget since Waterworld. On the other hand, the first two movies are some of my favourite SM stories, period.