As another who's been through the authentic areas, I am stunned to hear Viva's mentioned. I will have to give it a whirl.

And you should see about Baja's in Orange, as well as the two on Dixwell in Hamden (Orale and Mazorca). They're both new-ish yet, but solid. Curious how you might feel about them.

Barring those - I still pine for El Charrito's, but don't get out to the Stamford/Greenwich border much these days.