The restaurant on ADM is Ponto de Encontro - good choice of fish and meat
As you walk down from ADM, you'll turn right onto Estrada do Farol (restaurant hill) first restaurant on the right is Vimar, very popular, typical Portuguese. Next is A Rede - ignore!! I also wouldn't go to either Primavera or Villa Medici - opposite Vimar, next door to each other, I think they're overpriced for what they are!
The last restaurant on the right before you get to the Mirachoro Praia hotel is A Marisqueira - another good Portuguese restaurant
Further down the hill Jota Lita, A Galé, Casa de Bife are all good, Maximes is nice, a bit pricier - for pizza, Mirage on the left and up some steps. On the 'out' road, Ele Ela (bit more expensive, very good, have to book!), A Vela and Taste - on the 'in' road near the chemist and up some steps is A Fonte - how's that for starters? By the way 'bife' on a menu just means steak, so bife de atum - tuna steak