Islam.
People may follow many biases against equality in Islam but trust me, i am a girl and i wouldn't be following such a religion have i felt i am not treated equally with rights in fact, i found it the only religion that provided me with as many rights as i have.
I personally think Buddhism, but I also believe you can be a feminist in any of those faiths if you look at them the right way (although religious people in your personal church may disagree). For example, in Christianity, if you look at the testaments that were conveniently left out by Constantine when canonizing the Bible, you will clearly see that women were meant to be an integral part in the church. Many would argue that Mary Magdalene (some would further argue that she was Jesus' wife) was meant to lead the church but that she got pushed aside by others. Also, in Islam, women are REQUIRED to be educated, and except for some of the backwards members of that religion, women are really educated and also very respected. Some take the form of dress as a symbol of oppression, but most of the Muslim women I have known are very independent and free thinkers, and they view their modest dress as sort of liberating. This is because they are free from being seen as sexual objects and can be themselves without having to worry about always being sexually appealing and pleasing. Other than that, people have already made good points about Catholicism and the female saints, Hinduism and Siva, etc.
So I think you can be a feminist in any religion, though you may have to contend with members of your religion who are backwards and uptight.
Islam. Most of the people have misconceptions about it but I don't have any. I am a girl and as a girl I think that I am very secured in Islam.I thank All-mighty God that he has made ma a Muslim.