This is the top pick, with its tall memory foam walls giving you more support than any other pillow out there. It's shaped to sit flush against a headrest and compresses to a manageable size which sets it apart from other travel pillows because it can lay flat against the seat back. Most other pillows have a rounded back, pushing your head away from the headrest. The Travelrest also has rubber grip dots to prevent slipping while sleeping. This pillow's spongy memory foam cushions the entire circumference of your neck, preventing your head from leaning too far in any direction and its adjustable Velcro strap means it can fit most necks. Better yet, the pillow exterior is removable and machine-washable.
While you can't pack it entirely flat, the Travelrest weighs less than a pound and compresses to a quarter of its size when rolled into its Velcro-strapped carrying case. The memory foam is super plush, quite firm, and offers excellent support with not much give. The downside of it is that it doesn't adjust the fit, and can push over-ear headphones off of the ears of people with shorter necks.