Lavazza Maestro Ristretto (aluminum) is as good or better than most of the official Nespresso capsules. Highly recommend. They can be brewed as Ristretto, espresso, and Lungo. I rate them 9.5/10 : r/nespresso
Lavazza Deciso Coffee Nespresso Capsules 10ct
Amazon.com : Lavazza Deciso Espresso Dark Roast Capsules Compatible with Nespresso Original Machines , 10 Count (Pack of 6) : Everything Else