I don't keep up with men's rights groups, but from what I've read, I think the most legitimate and important issues are:
1. Bias against boys in education. We even went so far as to pass legislation favoring girls (pushed by a feminist organization). In my mind to create a bias against children (boys) is absolutely inexcusable and needs to be changed.
2. Healthcare: There are many ways males are disadvantaged in our healthcare. We have a Bureau of Women's Health, but no Bureau of Men's Health. Women's cancer research receives more money than men's cancer research. Obamacare mandates many healthcare advantages for women only, but none for men only.
3. Biased sentencing and other legal biases: Studies show blacks receive harsher sentencing than whites but the gap between men and women is even greater. Colleges are now handling cases of sexual assault in ways that are purposely stacked against accused males, denying them due process. Efforts of groups like the innocence project show many innocent males have been wrongly imprisoned. Under VAWA, male victims of domestic violence are routinely denied help and men are assumed the instigators even though many studies show women initiate more domestic violence than men do. We also have laws that legally advantage women in job hiring and in business ownership. All these biased laws should be changed to be gender neutral.
4. Family law and relationship issues: Marriage, divorce and custody laws are biased against males as are many customs/social pressures. It's much more acceptable for a woman to not work than a man for example. There's pressure for men to take on dangerous work to support family.
I certainly don't think men are oppressed, but I do think there are some inequities against males that need to be addressed. Again, I think biases against children are the most important to address.