DC has Wonder Woman. She's iconic and has been well known in society for decades. With the added popularity of the TV show in the 70's , she was further ingrained in popular culture.
She's a big gun in the DC universe, along with 'Batman' and 'Superman'.
Other publishers have strong female character too, such as Dynamite's 'Red Sonja',
...and Top Cow's 'Witchblade' to name a few.
And DC doesn't just have 'Wonder Woman' in their stable of big name female characters, 'Supergirl' and 'Batgirl' are major players that are publicly popular and probably could carry their own movie.
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But where is Marvel's strong female hero?
If your going to be honest, there isn't one female character in the Marvel universe that comes close to DC's.
Only recently 'Black Widow' has hit the main stream, and is beginning to grow in notoriety and popularity. But who else? Karen Danvers? Jennifer Walters? Jessica Drew? The general public doesn't know these names. Although they have the potential to translate into good films, they don't have the recognizable names such as 'Wonder Woman' or 'Supergirl'
Marvel needs to put those billions to work to hire the best, creative minds to develop a character already in the Marvel U. , or a totally new one!
I don't favor Marvel or DC (I like them both)and go with what characters I identify with. What's strange to me is that Marvel has not - with all it's creativity and cash - been able to popularize a female hero of their own.
Maybe it's because Marvel's female hero's never really had the exposure that DC's did.
The only exception was Susan Storm-Richards. She appeared in a cartoon with the FF back in the 60's and has had some exposure in the two films. Despite being all a hero should be-strong, smart , inspiring, etc.- , she's part of a team ; singling her out as a major independant character would be impossible.
We could talk about the X-men too. Since the TV cartoon in the 90's, and the three films , people have definitely become familiar with 'Storm' and 'Mystique' for example, but again they're part of a team . However, if Marvel were to invest in one of them somehow to try and 'mainstream' one in paticular, it could work. Maybe give one of them a TV show for a few seasons and go from there. I've read here recently a few TV projects featuring female hero's are being developed.
It's possible Marvel's already working on creating their own 'Wonder Woman'-I wouldn't be surprised- but so far , this is a subject where DC dominates...for now.