"Famously friendly" pooch, per the American Kennel Club

LAB

This popular retriever’s three-letter name starts with the same sound as "love."

This clue refers to the Labrador Retriever, often called a "Lab," which the American Kennel Club highlights as one of the most popular and famously friendly dog breeds. The word "pooch" is just a casual term for dog, and the clue relies on the AKC’s well-known reputation for ranking breeds by temperament. Since "LAB" is the shortened, common nickname for the breed, it fits neatly as the answer.