Portofino is our favourite restaurant in Vegas - hands down.
It's not the food that's the best, it's not the atmosphere that's the best, it's the magical combination of everything that comes together to create an amazing experience. Every time my wife and I go down to Vegas, we usually do Thursday-Monday. Our "last supper" is always at Portofino in the Mirage.
Favourite appetizers: Caprese Salad (unbelievably fresh and delicious), Meatballs (the goat cheese is a great touch, and the Arancini (huge chunks of crab with an amazing pesto aioli).
Favourite pasta: Ripatelli, closely followed by the Pork Cheek Ravioli. My wife absolutely loves the pasta special with lobster and white sauce they had on in late August when we were there last.
Favourite Entrees: Dry boat scallops are ALWAYS perfectly cooked, and the Veal Osso Buco is incredible and flavourful, especially with the saffron risotto and bone marrow.
And don't forget to pick something from their extensive (and fairly priced) wine list, or try one of their many incredible cocktails. The service is also incredible.
I'll tell anyone that will listen to try Portofino!