I stayed at the Wynn in 2005 when it first opened and I don't know why it took me so long to come back! It is still every bit as beautiful and luxurious as it was 7 years ago.
Service is excellent and the rooms are incredibly spacious. If I had to knock them for something, I think the beds (in two bed rooms) are full size when they could be queens. We had a great view of the golf course which has unrealistically green grass! We also got a room on a non-smoking floor (without even asking) which was a big plus. Apparently the gym (included in the resort fee) is also amazing, but of course I conveniently "forgot" my gym clothes.
The location is super convenient and just a short walkway to the mall and the Palazzo and Venetian. Caesar's isn't too far away either. You have a near infinite choice of restaurants and shops near by.
Oh and of course the casino. Be sure to sign up for a Red card if it's your first visit. You get $10 in free slot play just for signing up, then a spin on the wheel with 350 points and two free buffets with 750 points. I was able to get 750 points in a day and my two buffets had a $100 value!