I just got back from a vacation in Oceania (which is why I haven’t posted in a couple weeks). The flight path home included a leg from Melbourne to Los Angeles. During the 15 hours of sitting, I thought to myself that it must be one of the longest flights in the world. As it turns out, it isn’t even in the top 10; it’s the 12th longest. I’ve mapped the geodesics of the top 20 commercial flights here. With the recent problems at Qantas (and with airlines in general) some of these may change soon, but these are the current paths. Note that, because I’ve used a Robinson projection, some flights that go over the Arctic Circle appear longer than they are, so I’ve added a color scheme and listed the lengths on the map.
Data source: http://en.wikipedia.org/wiki/Non-stop_flight