I have a new drug-of-choice for long-haul. I only fly for pleasure and usually after saving up for the C or F cabin.

Like MegatopLover, I'm usually pretty fired up about the trip and find it hard to get to sleep. I find that .25mg of Lorazepam every three or four hours lets me drift in and out of sleep as needed without intractable sedation.

Before that I was a Halcion fan, but I find the new regimen works much better for me.