When is CES? I'm going Jan 11-15th. I went in the summer last time. In terms of clubs, food I can help you out.
Bellagio and Wynn have the best buffets. Rio is a mid level buffet, but very good for its price. Between Bellagio and Wynn, I'd pick Bellagio. Go before 5pm. Get in line BY 4:30 at the latest. I paid at like 4:55 last time and it was a weekend lunch price. What was it like $27.99 or something? Or $21.99? I forget, but it was dirt cheap compared to the dinner price. By the time I got seated, walked up to get my food, they rolled out the Kobe sirloin and all the dinner stuff. Yum yum.
If you show up at 6pm like an idiot, be prepared to wait 2 hours. It's what I did at Wynn. Never again.
In terms of clubs, the best clubs to me are:
Thurs: Surrender. Fri: XS, Sat: Tao, Sun: XS. These are the megaclubs.
Throw in Rio's Voodoo Lounge if you like a more mellow entertainment on the 51st floor.
People always love showing up late to clubs, but if you show up to the megaclubs by 9:45 or so, you can easily get in for free, provided that you have a 1:1 ratio at least of guys to girls. People who need to buy off the doorman, foolish. I didn't pay a dime to get into any club last time with 3 guys, 3 girls. The best way to get in is to find a promoter and text them. There's a list of them at some sites, or you can ask me for a few #s. Just text and they're more than happy to give you free tickets.
Foodwise, the steakhouse at Venetian or Palms is very nice. Lawry's is still good as always.