Hi i searched a long time for a fairly good deal as our flights are really unsociable and the kids will be a nightmare travelling at 2am in the morning, i found ramada the best deal for me as its next to gatwick with transfers to outside for a couple of quid. On the main page wait for the banner to change top right and it will say PARKING AND ROOMS FROM £75. If you click on that it will say from £89 down the bottom but when i clicked it and put in the dates i only paid £79.00. The room itself is £52 and the parking works out at just £27 and not so miserable kids.
I know its prob not a hot deal but its been a deal for me and thought it might help someone else, i think this may be the same price for other airports too