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 :
Nespresso's Ristretto, Espresso, and Lungo Explained (What's The Difference?) – The Green Pods
Espresso Lungo - 20*10
Ristretto, Espresso vs Lungo: What's the difference? - YouTube
Ristretto, Espresso, Lungo: Different Brew Styles with the Minipresso – Wacaco
Amazon.com: Barista Moments - Italian Ristretto, Strong & Lungo Espresso 120ct Variety Pack Compatible with Nespresso Machines (Variety, 120) : Grocery & Gourmet Food