I guess it's only technically a European flight, but I booked myself a ticket on the very limited Air Saint Pierre service from the French overseas territory of Saint-Pierre & Miquelon to Paris. They only run 12 return flights next summer (once a week) crossing the Atlantic in about 5 hours on a 737.

Apparently, given the short runway at FSP, the flights are weight limited to 100 pax so about a third of the seats cannot be sold. Just like Club Europe