We got a great weekend deal at the Copthorne Manchester. We paid 69 pounds per night (about $100) for a nice room with a queen bed and a view of the canal. It's a business hotel, so weekend rates are cheaper. Plus, we were there in March.
Location is outside of downtown Manchester, but it is very convenient to a tram station. From the hotel, you can walk to Old Trafford, Salford Quays, and the Lowry.