Hands down, it's Gelato Benissimo. Light & fluffy, flavorful and handmade daily--I love it! The gelato is made from organic milk. Flavors range from stracciatella, vanilla, mint chip, cappuchino, lavender, to strawberry, passionfruit, and guava. Yum. Different flavors every day, depending on what's in season/available. 328 Montezuma Ave, Santa Fe, NM 87501 (505) 984-9104. It is kind of hidden from the street, behind Fatso (bar, I think). The place is a gem & I think it would be more popular if it weren't so hidden. Regulars frequent it, though.
By the way, I went to Ecco Espresso & Gelato from other reviews & it was horrible. Super sweet and not much flavor. I was rather disappointed. I have been very selective about my gelato since I've traveled to Italy.