I'm a huge fan of the Wynn/Encore.
I ate with a group at Jean-George steakhouse in Aria a few years ago, and they did really poorly - food was Ok, but the service was frankly terrible. With so many great choices in Vegas, they only get one chance, and they blew it for me.
On the other hand, I just ate at Sinatra's for the 3rd time in 3 years! I love the vibe of that place. I talked to our waiter (Jay) on our last visit, and he told us that Mr Wynn wants everything to be perfect all the time - he's clearly got his finger on the pulse of the property and everyone cares about the experience, and it shows.