Marriott and Sheraton Skyline on the Bath Road are pretty good.

I've used most of them along the Bath Road and they are all pretty much the same. If you are not a tart for the miles of a specific brand, then the Marriott would probably get my vote.

The Radisson whilst offering decent runway views has gone down hill in recent years.

Personally, with a flight out the following morning I'd probably go for the Hilton at T4, I know you said it wasn't your favourite, but the hassle of getting to T4 from the Bath Road before a long haul flight, unless you (or the company..) are going to pay out for a hotel car to take you there, would swing it for me.

Haven't used it myself but the Jury's Inn Heathrow is a new property and T4 side, maybe worth a go.