The U.S. retail landscape has its fair share of underperforming, out-of-date properties, but the highest-quality malls are still attracting shoppers in droves, raking in more than $1,000 per square foot, well above the industry's average.

According to boutique research firm Boenning & Scattergood, the 20 most valuable malls in America that are owned by real estate investment trusts bring in roughly $21 billion in retail sales annually.

So-called A malls owned by the likes of Simon Property Group, General Growth Properties, Macerich and Westfield have little to no vacancy today, thanks to those landlords and leasing agents being quick to sign deals with new tenants as department stores and specialty apparel retailers flee.