I don't necessarily mean a "direct translation". IE, lift Black & Blue and translate it to the big screen, frame-by-frame, like they did 300. (Although that'd be cool. )
The idea I'm trying to get across here is that moviegoers are going to get as tired of superhero movies, as they were in the sixties over Western movies. (Something like half of all movies produced in the late 50s to early 60s were Westerns- John Wayne alone did something like 170 movies, over half of which were westerns.)
At some point, moviegoers are going to want something new. Not a reboot of a rebooted reboot. New and interesting.
And webcomics offer something like that. Girl Genius would make an excellent one, but the storyline would have to be drastically pared down, and two thirds of the characters omitted or deleted.
Questionable Content makes a great webcomic, but isn't quite wild enough to make a good movie. You could make something of the "illegal robot fighting league" thing, but there's no reason to buy that particular property from QC- besides, it'd be seen as a ripoff of Real Steel.
One I'd LOVE to see would be Spacetrawler. It's a very well done, standalone storyline, that with only a little bit of paring down, could be pretty easily turned into a movie. Live-action-with-CGI like Guardians of the Galaxy, or all-CGI like Zootopia.
Some other sadly-long-departed strips that would make for a good movie might be Sin Titulo (archives unavailable) which was a pretty good psychological thriller, Twenty Seven, which would be another sorta-horror thriller (and which the authors have already tried to pitch as an indie short film) Fleep, which takes place entirely within the confines of a single phone booth (and unlike Phone Booth, I mean entirely within- neither the protagonist nor the audience can see past the walls of the booth) Bookhunter, by the same author, or the long-dead and oft-lamented Monica Furious, which would make a great cyberpunk, digital-future action flick.