There is a new and usefully located hotel at Manchester Airport- the Tribe Hotel.
It is an Accor Group Hotel, and is across the street (on what is apparently called Chicago Avenue) from The Station (the combined bus and railway station)- a very well signposted 5 minute level walk.
I was at the airport yesterday and had an hour on my hands due to a cancelled rail connection so went exploring and found it.
It part opened last October, and fully at Christmas.
It's location means it is accessible to all terminals on foot via The Station.