For Fresh Seafood in Kos, Go to the Source: Mastichari
Mastichari is a small fishing village on the north coast of Kos. Here, you'll find scores of octopus lined up on strings hung here and there curing in the sun or in the cool evening air depending on when you visit.
It really is an authentic fishing village and the best spot I found for fresh seafood on my recent trip to Kos.
Honestly, I can't remember the name of the restaurant I ate at right near the pier, but the only other patrons seemed like locals and the food was a collection of genuinely, traditional fare.
We had an assorted plate for two with an array of known and never seen before local eats.
(As a bonus, this was where I was introduced to Tsipouro — a strong, clear Greek spirit approximately 45% alcohol by volume made from the residue of the wine press. It became my go-to spirit easily beating out ouzo.)