Aer Lingus are starting some new routes from London Gatwick to mainland Europe from this April and have some very good introductory deals.
A couple of examples; return 2nd to 9th May:
NICE £27.98 Aer Lingus (Next Best Price £76.31 Easyjet)
VIENNA £27.98 Aer Lingus (Next Best Price £73.93 Easyjet)
They do charge extra for Check In Baggage, but then so do Easyjet, Ryanair and most of the other discount airlines.