My tuppence worth:
Club Gascon is wonderful, the tasting menu with wine is guaranteed to send you home reeling. But you have to be okay with Foie Gras.
Le Gavroche - a nice experience but so not 22nd best restaurant in the world.
Waterside Inn - great evening but wish we'd gone to the Fat Duck also in Bray.
St Johns - really great food, but very meaty / offally. Plus your surroundings are a bit public school canteen. I love it but not everyone does.
The Ivy - great experience and nice comfort food but really hard to get a prime time table. You can combine it with a show as 6ish tables are easier to get?
River Cafe - not quite up to the hype but still a good meal.
Skylon - I enjoyed my lunch here, great views but its a bit hotel decor imo and the cooking isn't spectacular.
Nobu - fine but not all that.
Galvin Bistro (the one on Baker Street) - really great food, at decent prices but hopeless service. I'd go back regardless.
On the wish list:
Petrus,
the new Mark Hix place (where Rudland and Stubbs used to be in Farringdon),
Cafe Anglais,
Oliver Peyton's restaurant at the National.