I wouldn't put the Aria at the top of my list of favorites in Las Vegas BUT when they have a deal (like they did last week after memorial day) and if you plan well, it really is a great place to stay. We got a room at a good price and with a resort credit of $100. We used the credit at the Thai restaurant Lemongrass, which was excellent (we're vegetarian, so this was the only restaurant that really worked for us). We used the pool, the fitness center, gambled a bit....as long as you avoid the extra costs the amenities included are very good. I think they are trying to be in a class with Wynn and Bellagio which they are not BUT they are also more economical and for a first time Vegas visitor I would highly recommend the Aria. Good hotel, very good value if you book at the right time.
If you get a chance head over to the Cosmo for the Marquee Nightclub...its worth it and we got in for free just for asking on a not very busy night....good experience and walking distance from the Aria, even for my wife in her heels.
The Wynn (and the Encore) are among the top 10 resorts in Las Vegas consistently. I've stay 3 times at the Wynn and the experience is always great.
There are problem spots as with all places on the strip. The casino is less fun and more snooty and everything is pricey but the Vegan options for dining and the general quality that is in everything at the resort more than makes up for it.