Spoken word, but I am very particular with my listening habits. I also have some items which are guaranteed to put me to sleep within minutes, and others which are there to capture my attention for several hours. (It once took me over 100,000 miles of flying to finish an audiobook read by David Tennant as his voice is guaranteed to put me to sleep within five minutes, no matter how gripping the subject matter)

I have a large collection of BBC Radio 4 dramas, almost the entire collection of Arkangel Shakespeare dramatizations, and audio novels in various languages on hand to pass the time on trains or on planes. I rarely watch on trains as it makes me train-sick, but I do have a small selection of video (primarily in English, French, and German) which I tend to rewatch on planes.

I also have at least 2-3 books in various languages in my bag at any time. I actually only purchased an iPod a few years ago, long after they came onto the market.