I assume you are staying in Playa Blanca. If you are prepared to drive or take a taxi (about 15 to 20 minutes) then our recommendation would be the Amura in Puerto Calero. It is beautifully laid out and does excellent food and is not the usual tourist menu but it is a bit more expensive than the average. My description of their style would be "fine dining". It is the big "colonial" looking white building at the west end of the marina.
When we stay in either Playa Blanca or Puerto del Carmen (that is even nearer) we always try to find an excuse for a "posh" meal there. Last year we did our own anniversary and later in the year a friend's 65th birthday.
There are also some great fish restaurants in El Golfo village (again about 15 minutes drive) with spectacular coastal settings.
If you wish to eat in Playa Blanca the first floor La Chalanita gets very good reviews (window tables are recommended) as a special occasion venue and is right on the front on the town promenade but is still on our list to try.
Where ever you choose I hope you enjoy the meal and the occasion.
(As a complete aside I think you are a very brave man to commit to writing "money no object" in connection with your wife's birthday)
thanks a lot will try one of them and after 29 years of her putting up with me she deserves a great nite out steve