I always try to do the most efficient thing I can do in any location. On airplanes, reading is the most efficient thing to do. Sleeping on airplanes in almost always sub-optimal. Working on the laptop is good (no interruptions) but still doesn't hold a candle to reading. There is almost no plane I get more reading done on an airplane.
My strategy for a flight is like many travelers I know ... first I stock up on all the magazines I haven't read and a I pack a really heavy bag. I try to also bring a few books along. On the place I devour the magazines first the lessen my weight and then I move to the books ... always leaving behind what I finish (United Airlines has had dozens of books donated to it by me over the years).
(I've also found that a shady place on the beach is a fantastic place to read ... I had time to experience this over the holidays ... there is probably no greater vacation for me than reading under a palm tree on a hot day.)