Affirmative action laws are far more likely to benefit women than men.
Selective Service only requires men to sign up. This means that in the event of a shooting war, the government has contact information for men to draft, but not women. I have a tough time believing that feminists will stand up and say "yes, you need to draft women".
VAWA, though (with the exception of the name) carefully written to not assume genders, is effectively gendered because essentially all resources allocated in the name of VAWA end up being devoted to protecting women from men. VAWA funds never go to male battered victim shelters, for instance, nor does it pay for abuse counseling for men (even though women are as or more likely to initiate domestic violence as men).
The government allocates far more money to female medical research than male, even ignoring money spent associated directly with reproduction. For instance, far more money is devoted to researching breast cancer than prostate cancer. This money is allocated by the US congress, effectively by law.
Perhaps the most stunningly obvious case of gender bias is simply in the government itself: There are thousands of agencies (literally) devoted to women and *NONE* devoted to men. Indeed, when doctors wanted to make a announcement about men's health, it ended up on the women's health care web site.
When activists pointed out that boys are more likely to be failing out, 20% less likely to graduate high school, etc and it was incredibly sexist to have a department of women and girls but not one of men and boys, the government actively resisted the idea of creating ANYTHING devoted to boys. Indeed, Obama recognized the major educational problems for black boys but would not acknowledge the gender component of it, he only acknowledged the race part of it.
For the record, yes, I supported Obama and still think, in balance, he was a great President. This is a place where he completely muffed it.
These things entirely ignore gender selective implementation of non-gendered laws. If a woman hits a man, it is usually ignored. If a man hits a woman, it is considered assault. Women are far more likely to get custody of children in a divorce, get a larger cut of the man's paycheck than if the genders were reversed, spend 60% less time in jail for the same crime, etc. These are things that the legal system enacts but require judgement - judgement which is far more likely to favor women.