I had the giant bone in ribeye at Delmonico's last year in the Venetian along with their parmesan black truffle potato chips. The steak was extremely good and the service was top notch, the chips are godly, I have not been able to recreate them to date.
It is a goal of mine to try out more of the top steak restaurants in Vegas but this year I am SOL as I got a job that starts May 10th and cannot go this year. Otherwise I would have likely tried to hit SW in the Wynn, supposed to be pretty good steak and if you can get a table on the patio it overlooks the lake of dreams show.
One place to avoid is the italian restaurant in the Fashion Show Mall, right on the corner of the building's second floor. One of the worst meals I ever had, got the veal and it was soggy, my friend got steak and a lobster tail and the lobster tail was mush, it had clearly been freeze/thawed more then once. Place was the pits.
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Maggianos at the Fashion Show Mall really good Italian food and reasonably priced.
this is the name of the place, my opinion on it is a complete 180.
For a decent Vegas experience there is a Italian restaurant in a strip mall immediately behind the Flamingo. About every star on the planet in the last 40-50 years has been there and has their pictures on the wall. All you can drink wine and the food is quite good, nothing amazing but decent for the price and the atmosphere is worth the trip for a old school Vegas experience.