First this isn't a question to start hate or anything like that. Personally I say men. I know women also have their own risks, but the biggest one I see is getting your heart broken. Whereas for men even if the wife was to cheat he still gets screwed. There's alimony, ridiculously high child support if you have kids (Sometimes even if they aren't yours), losing your home, you car, and other personal property. A guy is lucky if he doesn't have a massive debt at the end out it all.
Most Helpful Girl
I don't know why these questions are always getting asked.
Just about every single risk that comes with marriage comes with dating long term. If you're with someone for more than 7 years you're screwed either way (yes you can still get hit with child support payments, lose your house, car, other possessions, etc if the courts have to get involved - which they usually do if you've been together that long).
There's no way to dodge these risks. It's not either get married or cohabit it's stay single or date long term1