On newer airplanes, if it's a long international flight, often you will have a personal TV screen, where you can select your own movies. And not just in first class :P I usually end up sleeping, even if it's day. I used to get nauseated on planes, so I started taking Dramamine for them, which has a pretty strong drowsy side effect. I discovered that I don't really feel sick anymore, but I still usually take one. If you can't sleep, things like sudoku, or logic puzzles are good for passing the time. I have an eight hour flight to America at 5 am tomorrow in fact. I should be able to sleep anyway on that, because I'll have to get up at the latest at 3 am to get to it.