What's the best kind of travel neck pillow?

If you're going international and it's 5 hours, don't bother with cheap. You will find it useless. Memory foam is your best choice. Your second best (and a lot cheaper) is the bean bag one with small beans inside. Don't waste your money on anything with feathers in it. It'll flatten out and not provide your neck with any support.

Some friends of mine sell travel related stuff like this online, good quality stuff, too, at TravelBaskets.com ... you could look and see what brand of neck pillow they carry.

Check out also http://www.magellans.com/store/In_Flight_Comfort___Pillows_and_BlanketsIF383?Args=

They have a supportive inflatable collar for $25 that got good customer reviews. Other good stuff for long, uncomfortable trips.

This one may meet all of your requirements. I like mine to be inflatable so that I can stuff it away and it won't take up too much space. It's also less expensive than a Bucky (which can feel like taking your teddy bear around with you) and is pretty comfy. You can also grab one at REI:

http://www.eaglecreek.com/accessories/travel_comfort/Compact-Comfort-Travel-Pillow-50025/?search=travel%20pillow

Second the Eagle Creek pillow. Just be sure not to inflate it ALL the way. Leave it a little squishy so it cushions your head instead of bouncing it around.