Chiming in here perhaps a bit late but +1 for Vegas. Simple 1 day (few hours) process to get married and you can get an Apostilled Marriage Certificate issued in 1 day by paying a 125 USD fee. You can also do it in a few hours (it costs 1000 USD or so) but that seems overkill.
The apostilled certificate is recognized almost anywhere. It's a certified legal document.
PM me if you want to know more about the process although I did it a few years ago - should be mostly the same..