Like
@paulcb , I prefer the disposable foam ones. My favourite is
3M EAR Yellow Neons - they are soft, conform to my ear canal well, and have excellent sound attenuation. The Yellow Neons are softer than the 'standard' 3M foam earplugs, and also have a rounded end.
I am aware that custom-fitted ones might be more comfortable, but the problem is losing them. The disposable ones cost very little if purchased in a large box of 100 or 1,000, and I can get about 3 days of use out of a pair before they become dirty (not from my ear, but from the time they spend in my pocket when I am not wearing them).
My younger sister spent some years working as an audiologist, and she advises me that there are considerable differences in the characteristics of ear wax from one person to another - some people have 'dry' ear wax, others have 'wet' ear wax. This might explain why a particular type of foam ear plug that one person raves about being really comfortable might not be comfortable for the next person. I think you need to experiment a bit with different types and different brands, and once you find ones you like, buy a huge box of them and stuff 'em in the unlocked fairing pocket of the motorcycle.
Michael
3M EAR Yellow Neons