Vueling have put many domestic Spanish flights on sale from just €17 one-way during the summer. For example, fly from Ibiza, Spain to Barcelona for only €17
Lufthansa currently have a sale from many Scandinavian cities to many US cities from only €243 roundtrip.
Cheap flights from Milan, Italy to Toronto, Canada for only €320 roundtrip with Lufthansa and Austrian Airlines.
Cheap flights from Munich, Germany to Pattaya, Thailand for only €400 roundtrip with Qatar Airways.
Cheap flights from Berlin, Germany to New York, USA for only €289 roundtrip.
Cheap flights from Vienna, Austria to Hong Kong for only €363 roundtrip.
Christmas flights from Stockholm, Sweden to Johannesburg, South Africa for only €339 roundtrip with South African Airways, SAS and Lufthansa.
Super cheap, non-stop flights from Barcelona, Spain to Boston, USA for only €91 one-way. Also works in reverse (for $138 one-way).
Fly from Milan, Italy to Bangkok, Thailand for only €333 roundtrip.