Spago at the Forum Shops is a restaurant you must visit if haven't already. It's an institution that has inspired many other restaurants on the Strip. If you like desert, you must order the Chocolate Souffle. It is the best Souffle ever! No other I've ever tried even comes close. All other chocolate Souffle's are weak in comparison (even my favorite restaurant Scarpetta, sorry Scarpetta). The Dark Chocolate Sphere is pretty good too. Their Spaghettini and Meatballs is great with the only downfall being that you might not have room for the amazing deserts.
The pictures speak for themselves...