I am convinced “best dog” generally comes down to proximity. Both figuratively and then literally.
Never met a dog who wasn’t the best., at least in that moment.
Including one that kept trying to set me up with her human. Betsy was an ancient basset and wouldn’t leave our office building without saying goodbye. If I wasn’t in the office, she’d literally hunt me down. And if her human tried to pull a fast one, the entire building would hear Betsy howling bloody murder.
Her human is lesbian, but she’s a good friend now. All because Betsy’s ears caused immediate and uncontrollable giggling when the dog walked by.