Wonder Woman is a weird character with a weird origin story and weird powers. She worked in a cheesier time, but for her to work now, I think her backstory would have to seriously be re-designed. Daughter of the Gods? Invisible plane? Magic lasso that makes you tell the truth? Just too goofy. I can barely suspend my disbelief when she pops up in cartoons anymore.
I think Catwoman could work well as a live-action series, as she is also a fairly independent character that wouldn't require shoehorning Batman into the story (not that you couldn't).
DC is a boy's club. There are plenty of female Marvel characters that could support their own series, but unfortunately you just don't have that many if you're exclusively looking at the DC Universe.
Most of Marvels female characters can't even support a comic book series, much less one on TV. Have any had the success of Wonder Woman, Catwoman or even Birds of Prey? Marvel has made some strides lately in introducing books starring women, but DC ha been doing it for decades.
Both of the major comic companies-heck, just about all of the US comics companies, are boys' clubs. But DC has a much better record regarding supporting their female characters than Marvel has, as NerysMyk pointed out.
For one, they've got the greatest female superhero Wonder Woman, and they've long put out solo and team books starring women, like Birds of Prey, Gotham Sirens, Batgirl, Supergirl, Powergirl, Catwoman. Even Voodoo got a shot in the New 52. So has Amethyst. And there's a new one coming with Katana. Female characters have also played major roles on many of the team books.
Marvel doesn't have a comparable record, especially when it comes to book solos. As Greg Cox pointed out, Storm is their most recognizable female character and yet has never had a solo series. Maybe a miniseries or two, but even with Marvel NOW her character seems to be used to grace book covers but no more. And now you have Captain Marvel, Sif, Red She Hulk, Fearless Defenders, and the all female X-Men squad, but DC is league's ahead of Marvel in putting out books like this. Mostly Marvel's female characters have gained prominence by being parts of ensemble casts.
Granted Marvel has put some female characters out there in solo books or miniseries (Black Widow, Elektra, She-Hulk, Spider Girl, Storm, Ghost Rider, Wolverine's Clone), but the record to me doesn't show they've been as strong about supporting them as DC has. Now we can debate the quality of the works DC has put out, but you can't knock them for at least making the attempts and continuing to make the attempts where female characters are concerned. Though I should give credit to Marvel for seeming to finally be getting on board. However a Storm solo is something they really should've done, especially when the first X-Men movies came out.