There are countless legal benefits to marriage ranging from automatic inheritance to joint tax filing to enhanced property rights to the ability to sue for wrongful death to... look, I could go on for awhile. Instead, I'll jump into three specific benefits of marriage in the employment context:
1. Health Insurance
Healthcare reform efforts notwithstanding, employer-provided healthcare remains the most common form of coverage in the United States. Often employers will provide or subsidize some form of health insurance for employees' spouses as well. Good luck finding one that covers your girlfriend (or boyfriend)!
2. Family and Medical Leave Act (FMLA)
I'm in the midst of reading a 500-page book on the FMLA right now, but in one really oversimplified sentence: You can take up to 12 weeks of unpaid leave a year to care for a spouse with a serious health condition. Hopefully you won't need this but if such a situation arises you'll be happy you're covered. Your significant other is not covered unless you are married (with a few notable state law exceptions).
3. Spousal Privilege
As an employment lawyer, I am all too aware that the employment relationship often leads to litigation. Without getting too deep into the nerdery that is evidentiary privilege, the marital communication privilege applies in civil cases. In other words, conversations between husband and wife are privileged. If you are the one in litigation then you can actually prevent your spouse from testifying against you and/or your spouse may refuse to testify.