We usually book a week at the Grand Chateau, booked as a getaway through II. Much less expensive! And we avoid the buffets, and instead opt for Capital Grille. Only buffet we've done is the Sunday Gospel Brunch at the House of Blues. Phenomenal spread, with energizing music and ambience.
I just saw they added the Cosmopolitan of Las Vegas as part of the Autograph Collection. It's much closer to the action on the strip - I'd recommend it. I stayed at the Marriott up north near the Hilton a couple months ago - it was okay, but nothing special. When I go back, i'm going to try the Cosmo for sure. Looks like it's pretty sweet.
I always pick Renaissance for consistent quiet quality. Very personable staff on every visit. They go out of their way to assure me a great stay every time. I have never had a sleepless night at Renaissance Las Vegas. No gaming in the property, but plenty of options for that, when desired. In many, many stays, I have witnessed zero hustles and zero hassles. There are many good buffets in Vegas, but I only visit them when time is an issue. Good luck!
I would stay at the Grand Chateau which is a Marriott timeshare. It is just off strip within walking distance of everything, go out the door and into the side door of Planet Hollywood. Of course the Cosmopolitan opens in January... Can't help with the buffet part...
Stayed at the Grande Chateau this past Spring, and it is very nice, and a good value. Problem is there is no restaurant at all, as they didn't build out the second phase. But close to everything, and Planet Hollywood is across the street. Rooftop bar and pool is nice.
It is really a personal choice as you will find everything you could want in Las Vegas. My personal choice is the Grand Chateau. Close to everything and yet far as you want to be. Check with the conceirge for some of the best options. Our personal choice for lunch was directly across the street at the Brazilian restuarant (don't remember name, its the only one.) Again, there are many other options including the Japanese Seafood Restuarant also across the street. Hope this provides some helpful insight.
I have found the Hughes Center, Residence Inn as a great Vegas get away. Located far enough from the strip to make you feel less bustle, but whiten walking distance, if so desired. Two bedroom suites are available and the breakfast is top notched. Next door is the Gordon Birch restaurant, which also happens to be the location for a Sunday morning Jazz fest.One block away is Lowrys Prime Rib Restaurant, one of Vegas's finer steak houses.