Originally Posted by
DangerMouse
I like
http://www.flylc.com for searching LCC carriers between specific city pairings. Simply input your Departure and Arrival cities; the website lists available LCCs that service the route. Additionally, one can work backward by selecting the preferred LCC (if applicable) and seeing what routes are offered.
FlyLc only shows direct routes. For a greater selection use a site which calculates routes by joining different LCCs together. the new
Skyscanner site works very well if you untick the 'Direct only' box. Using this you can look up any European city to any other European city. It also includes legacy airlines