The Rennessance Hotel on 7th Avenue is fantastic--great staff, great rooms, nicest and roomiest bathrooms I've ever had in a hotel.
I've also stayed at the Hilton Times Square. It's only a couple of years old. It's very funky. Great hotel.
The Marriott Marquis is nice as well. The one thing I didn't like about the Marquis is the elevators always seem to be crowded even though there are about 10 or 12 of them. Sometimes you have to wait a long time for an elevator.
The Doubletree Guest Suites is awesome. You'd get a two room suite with two TV's, three telephones, a fridge, and a microwave.
The New York Hilton and Towers on Sixth Avenue is fantastic, too. Very convient. Sometimes they offer rates as low as $149 online.
As pw2pp said, you may want to try Priceline as well. I got a room at the Shearaton New York Towers for $120 for two weeks form now. I believe I chose the mid-town central area to get that hotel.
Karen