A little tip in case you decide to do the Bellagio buffet, as you're going solo, instead of waiting in line if it's busy, you can go in the back entrance & seat yourself at the bar. They'll probably expect you to buy a drink (liquor or beer or wine) with dinner if you're at the bar, but probably not required. Great way to skip the line if you don't mind sitting at the bar instead of table.

ALso, Spice Buffet at Planet Hollywood is pretty decent - though Wynn is probably one of the better ones in Vegas (of course, the seafood buffet at Rio is always spectacular!)