My favourite is London Stansted (STN). I flew Buzz Air from there this past May to CDG and return.
This is a picture of my own, not one from airliners.net:
The aircraft is the one I flew to CDG, G-BTTP. In the background is an Air Botnia F28.
The layout of Stansted is almost ideal. High ceiling, bright and airy with an open layout that makes is very easy to find everything you are looking for. Shops and restarants are nothing to brag about but are unobtrusive and functional. The walking distance is minimal, an automatic train takes you to your gate.