Ovda
If a London-Ovda route returns, it will almost certainly be from Luton or not at all. Ovda / Israel is offering some hefty subsidies to airlines bringing in foreign tourists and Ryanair has made use of this in a big way. The only catch is that while routes like Bratislava-Ovda have had healthy load factors, Luton-Ovda has sometimes had quite mediocre load factors - not sure if there is enough demand for a 5h30 flight to a destination which is expensive in GBP terms