I'm not a huge fan of the foam ear plugs and find 3M's "Peltor Sport Tri-Flange Reusable Earplugs" something that's comfortable for me to wear on long international flights to sleep. The downside of the non-foam design is 26db vs. 32db. They are around $5 for a three-pack.

https://www.3m.com/3M/en_US/company-us/all-3m-products/~/All...