Best sound proofing?

[elkoi]

Whats the best sound proofing to buy? because theres loads on Ebay, just seeing if anyone could recommend me one to buy? thanks.

[Tontsy]

brownbed.

or if you can get industrial proofing, that :y: and expanding foam, depending where you want to put it.

[stevo67]

Dynomat soundproofing mate.