Best ear plugs for both sound quality and reduction

I use the Loop Ear Plugs.  They are popular with my concert going friends.  Inexpensive and do the job.  They come with a variety of swappable size adaptors.  Cheers

I used to use Kleenex until I realized the sound in concerts is terrible and too loud and I do not like looking at musicians... I like listening to music, and for rock and amplified concerts it sounds much better at home. I haven't gone to an amplified concert in over fifteen years. 

Like others have mentioned, customed fitted by an audiologist are your best option. I have Westone with three attenuator selections.

Thanks for all the input. I agree that a custom fit is the best option. I may order something in the meantime to have on hand, like the loop or etymotic off the shelf. 

By all accounts custom-fit are the best, but for an inexpensive option, I've been very happy with the Etymotic ER20. I've been wearing these at live concerts for years. I haven't tried others, but I've been very happy with the level of attenuation as well as the frequency balance that they provide.  Pro tip: Keep a pair in your car so you're always prepared.