Grimaldi's is the real deal. My wife and I tried to go to the one in Brooklyn but got there too early and didn't want to wait so we weren't able to try it until we went to their restaurant in Vegas.
We had high expectations and it did not disappoint. It is hands down some of the best pizza I've ever had. I heard they have some locations in California that I'm going to try and the next time we go to Vegas, we are going back. We are big fans of Grimaldi's and highly recommend it.