I just stayed at the Holiday Inn 57th Street for 4 nights, which is on W. 57th between 9th and 10th Avenues. I paid $157 per night (Nov. 11-15, 2009), AAA rate, which effectively works out to $175 per night with taxes. I booked on the Holiday Inn website about 60 days in advance. [About 30 days prior to arrival, the price quoted was higher, around $202.] It may well be possible to get a reasonable price for a fancier property on Priceline, but I didn't bother once I booked this rate. The rate seems lower due to the recession and may increase with a recovery.
I found this to be a great location and a decent place to stay. This is not a luxury hotel, but it offered clean rooms and efficient service. I have zero complaints. There is a $2 per bag storage charge.
Arrival from Newark Airport was via the Olympia Trails bus to the Port Authority bus terminal. then via A-C-E subway to 59th St., exiting at the 57th/8th SW corner exit, about 1 and 1/2 blocks from the hotel. On our return, we used the M11 bus down 9th Avenue. $27 for an unlimited MTA 1 week pass.
A great nearby breakfast restaurant was the Flame, on 9th at 58th. We liked it so much that we returned 3 more times.
It was an easy walk to Lincoln Center, about 6 short blocks (Metropolitan Opera). The theatre district and Central Park were also within easy walking distance.
The neighborhood has lots of restaurants and shops, and appeared very safe.