I agree that the Vsonic GR07 are the best sound quality for the price, but I found them to be much less effective at isolating external sounds than my previous Shures and Ety's. I just ordered some Airbud tips, and am going to see if the various Shure/Ety tips I have will fit.
If OP is actually asking about earplugs, as asked, rather then music listening devices, as answered, Leight MAXs are the best I've found, at NRR33. And at about $1/pair, hard to beat in price. For the ultimate isolation, I've wrapped a set of PlaneQuiet NC earmuffs around them. But I do that rarely, as it's bulky and much more to carry.