What about Aer Lingus? When I was there we used to have to fly Dub - Snn - USA -Snn - Dub every time. So probably very high cycles on the B707s and B747s. Not sure about hours, though. We also had a A330 (EI - SHN) that, apparently, had the highest cycles (or hours) I can't remember, in the world. I think it ended up in Portugal. Now scrapped.