My wife and I plan to go from London to Vienna on July 7, 2014 We have our flights already booked from Vienna to US.
So far we've found flights as follows:
British Airways from Heathrow 400 USD
Easy Jet from Gatwick 306USD (includes $54. extra cost of 2 bags)
We will be leaving from a hotel in the Bloombury area Not sure if airport choice is significant.
Also, glad to hear of other airlines -especially current specials. Appears that Ryan Air is not a viable choice.
Joe and Diane
Boston, MA USA