Small rooms but great location
Just completed a weekend stay at the Hampton Inn Madison Square Garden.
The hotel is a great option for staying in the city at a reasonable rate. However, we were there over the Labor Day weekend so the cost was hiked a bit from what you would probably pay ordinarily. But other hotels were as well so this was still one of the least expensive options.
The hotel is typical of a Hampton Inn you would find elsewhere. Comfortable beds, free internet and breakfast. But, the rooms seemed quite small. Not necessarily by NYC standards but definitely smaller than other more suburban Hampton Inn properties.
The staff was welcoming and polite. 
The key attraction for this hotel though is the location. It's on 31st street just steps off 6th Avenue right in the heart of Midtown. It's close to Times Square, Madison Square Garden, The Empire State Building and most any site you want to see in the city. And even though it's close to everything its still pretty quiet. We had no noise issues during our stay which can be a problem in Manhattan.
Our only real complaint was the cleanliness of the hallways. While our room was quite clean, the hallways were in desperate need of a good vacuuming. Not a big concern but worth noting.
Overall, we were very happy with our stay and got exactly what we were looking for.