Marvel has had no box office bombs. That is to say, the only fully funded and independent projects that Marvel has put out are Iron Man, Iron Man 2, The Incredible Hulk and Thor. Captain America is not out yet, and neither is The Avengers. If you are talking about Marvel based movies in general, any short comings there, come down to the poor efforts of the studio that holds the license to that property. Even still, the only genuine flops based on a Marvel comic properties are Howard the Duck and Punisher Warzone. Other than that, Marvel properties have been successful. Even the more questionable fare has been a boon for investors.
Fantastic Four: Budget of $100 million, gross of $330 million.
Rise of the Silver Surfer: Budget of $130 million, gross of $289 million
Ghost Rider: Budget of $110 million, gross of $228 million
Elektra: Budget of $43 million, gross of $56 million
Daredevil: Budget of $78 million, gross of $179 million
X-Men Origins: Budget of $150 million, gross of $379 million
Blade Trinity: Budget of $68 million, gross of $128 million
Men in Black II: Budget of $140 million, gross of $441 million
Spider-Man 3: Budget of $258 million, gross of $890 million
Those are the Marvel films that have had questionable reception, but as you can see, the box office results are still impressive, save for Elektra, which at least turned a profit.
On the other hand, DC has had a number of flops.
Jonah Hex: Budget of $47 million, gross of $10 million
Catwoman: Budget of $100 million, gross of $89 million
Superman IV: Budget of $15 million, gross of $15.6 million
Steel: Budget of $16 million, gross of $1.7 million
Supergirl: Budget of $35 million, gross of $15 million
The Spirit: Box office failure on opening day. Budget Unknown
That is not to say that there have not been a history of successes. In most cases, even the most loathed DC comic films (Batman & Robin) tend to be a success. They have a lot of success with lesser known properties. Watchmen, V for Vendetta, Constantine, Stardust and Road to Perdition were all strong performers or outright successes. Ultimately, DC does have the most spotty track record, but I really don't see how any of this is productive conversation. Now you all have the facts. Hopefully you can move beyond this Marvel vs. DC debate and move on to core of what made this film work, and what didn't work.