Personally, I've tried disposable foam, cheap reusable silicone/plastic earplugs, Plugfones Motorhead and Auritech Bikers.

Disposable foam - the most silent of em all. But a bit too silent. I'm using intercom, barely can hear anything unless it is at full blast. Claimed NNR is 30 dB.
Cheap reusable silicone/plastic - just wore this once or twice, the material kinda chafes the ear.
Plugfones Motorhead - blocks most of the wind noise. But if your helmet is tight around the ears, tends to move the piece out of the ear. Claimed NNR is 25 dB.
Auritech - easy to use, but it seems not as silent as I wanted it to be. I think this could be because of it is a bit small in diameter. Claimed NNR is 24 dB.

So, who else wears earplugs and what brand/model/type do you use?

Some reading and quote sources:
https://www.revzilla.com/common-tread/avoiding-hearing-loss
http://www.webbikeworld.com/r2/earplugs/