London Restaurant with a Good View
 

I'm looking for a good London restaurant to celebrate a 25 year anniversary.

Desired features:
Fabulous view of London
Good service
Delicious food (From New Orleans so expectations are a little high...)
Ambiance
Value for the money (It is a 25 year anniversary so I am definitely willing to spend more if it is worth it)

I have seen quite a few mixed reviews of OXO and Paramount, but should these be discounted?

Any help would be great!

Three places that spring to mind:

The restaurant at the top of the National Portrait Gallery

http://www.npg.org.uk/visit/food/restaurant.php

And for amazing food and beautiful views of Hyde Park at street level (book WAY in advance):

http://www.dinnerbyheston.com/

For fabulous and elegant Chinese (great duck!) and spectacular views across Hyde Park, Min Jiang:

http://www.minjiang.co.uk/

It's pretty hard to get value for money as restaurants with views tend to command a premium (and come with the obligatory silver service/white tablecloth affair). I would discount the Oxo Tower as, you're right, the food is hit and miss (it is frequently cited at london most overated dining experience by Hardens). I will echo LondonYank's suggestion of the National Portrait Gallery – it's pretty good value for the location, though not particularly high end.

Skylon at the Royal Festival Hall has views across the river and is big, buzzy, smart and fun:
http://www.skylon-restaurant.co.uk/restaurant/

Drinks at the OXO Tower after the dinner.

first rule of thumb (anywhere) - restos with great views tend to have mediocre food esp for the price.

Another vote for the Portrait restaurant (as mentioned above). Food and service are terrific and it's not too expensive by London standards. Good view at night over the rooftops of Trafalgar Square with the Houses of Parliament in the background.