I am going to London for a 4 days in Feb/Mar and was scouring the net for a decent hotel.
There are over a dozen hiltons i London and there are deals to be got if you are willing to gamble on a non-refundable room. I booked a double room with buffet breakfast in the Hilton Paddington for STG£95 per night. Rooms have wifi, LCD, air con etc. Rooms are accessible from Paddington railway station by escalator!!! Paddington is also only 15 minutes away from Heathrow on the Heathrow Express.
( I will probably recoup some of my money at the buffet breakfast!)
There are similar deals in other Hiltons across the UK.