Gotts in Napa used to be Taylor's refresher I think. They had to change their name as the original Taylors is still in St.Helena. Good burgers but my favorite is Andies burgers on Freeway Drive just North of the Outlet Shops.
My wife says Buckhorn in Downtown Napa has the best burgers @ $6.99

I go once a month to Phylises ( sp ) in Novato for a mushroom burger. Its good! with a retired friend of mine. We have been in more burger joints than the average person.

And, as several folks have mentioned, I cook a good burger myself!

Cheers!