It's not the most beautiful, nor the most romantic. It doesn't have the best dining options, nor the best clubs. It doesn't have great shopping, nor a great show. So why do I like ARIA?
I like ARIA because it's in the center of City Center. The hotel is clean-cut and simple. The restaurants are all safe and pretty solid (American Fish won't disappoint!). The club Haze is mediocre but they offer plenty of lounges that are quite chill and not overcrowded and don't charge cover (Gold Club upstairs or Deuce downstairs). It has a convenient tram to Bellagio and Monte Carlo.
Overall the rooms here are all solid and beautiful. Very similar to the rooms at Vdara but missing the kitchenette. Very comfy beds.
If you want something safe that's still quite high end, Aria is a good choice. If you want high end dining options opt for the Wynn or MGM and if you want good shopping and a more romantic getaway then opt for The Venetian.