I came here with family in 1999.  I believe I had a lot of fried seafood and a lot of shrimp cocktail (the quintessential Vegas food) and raw oysters.  I  got one of the worst case of food poisoning I've ever had.  We drove down to check out a bunch of colleges in so cal.  I remember throwing up in multiple college campuses including UCLA, the school I ended up going to.  Since 1999, I've been back here a few times and no food poisoning so they're okay in my book again.  I think the key is to not overdo the cold or raw seafood as they are breeding grounds for bacteria.