I've used two primarily:

Alpine MusicSafe Pro

Etymotic Research ER20

I'd say both are comparable. Though the Alpines come with three filters allowing you to select the level of attenuation.

The Etymotics are bit longer so stick out your ear a bit funny looking, but they're more cone shaped and are easier to put into your ear.

The Alpines come with a little tool that helps inserting it into your ear.

To be honest they're both quite cheap so try both and not break the bank.

If you want to go higher end you can get ones where you can get a custom mold to your ear canal. But I don't have a recommendation there.

I got a pair of Etymotic’s ER20 ear plugs after seeing a few recommendations here on HN. I’ve worn them at concerts, at loud events, in a hotel next to the freeway, and even in the car when the driver had the radio too loud for me. Highly recommend them. I have small ear canals and the foam earplugs never worked, but Etymotic’s “standard” fits me fine, and also works for another friend with normal ears.

https://www.etymotic.com/consumer/hearing-protection/er20.ht...

https://smile.amazon.com/dp/B00G0PPTAK/

I personally use squishy foam-type ones at concerts (and when I played in a band) and find they make music sound better by isolating the individual components of the band. They are far from fancy, but I have not had ringing in my ears after a show since I started using them. I wish I had been smarter as a teen.

See: https://www.amazon.com/Macks-Ultra-Soft-Foam-Earplugs/dp/B00...

A lot of concert venues have these: https://www.amazon.com/Howard-Leight-Honeywell-Disposable-LP...

They're comfy and they sound pretty good. Unlike some others, they only reduce by about 12dB, which brings a concert into the safe zone while retaining good clarity. The more reduction you have, the more bass-heavy the resulting curve is, which doesn't sound too good.