How long can a steak marinate before it goes bad?

I had this steak marinating for a few days. I can't remember exactly when I put it in the marinade, but it was in the fridge no more than five days. Do you think it is still good? I have smelled it, but it just smells like the marinade, which included vinegar. The one on the top is what the top portion of each steak looks like, and the bottom is what the bottom portion looks like. I think they look a little strange. What do you think, should I try to cook them or just throw them out?