A couple of updates to note for the master list in post 1.
Hilton Manchester Deansgate
- lounge usually has more than bacon and eggs. You can definitely add sausages to the list at least.
Hilton London Metropole
- I have always had a full breakfast in the restaurant as an option as well as the lounge.
Also, we can add on:
Doubletree Tower of London
- full restaurant breakfast including a la carte options. (no lounge)