The best of anything depends on you. Which is why there are so pillows on the market. I prefer to use the ones that are adaptable to different situations. En Route has two options here:
1) the neck pillow that adjusts from a square pillow to a U-shaped pillow by unzipping and shaking the beads inside into shape. Then unzip the hoodie compartment and have a privacy screen for your eyes.
2) The Comfort Cushion is my go-to a lot of the time because it can squish into the gaps in a window seat. It can also be a lumbar pillow, seat cushion, or a foot rest. Sitting on it in the plane or in a car, can help with circulation as the beads move with your body.
Inside the Comfort Cushion is a blanket (your personal blanket so it's sanitary) as not all airlines provide blankets. The blanket can also double as a beach blanket or shawl in the evenings. Sometimes, I'll replace the blanket with my puffer jacket for warmth and to carry my jacket around when I don't need it.
Again, there are so many options to consider.