Athens+ mediterranean food and 1 short weekend

I'm heading to Athens this weekend and am looking for dining ideas. I'm sure there will be endless places but is there ONE I shouldn't miss? I'll be staying at the Hotel Grande Bretagne at least one night and from the reviews I've read I shouldn't miss the Roof Lounge for cocktails and the view. I probably won't have dinner there as I want to keep the $$ down. I love to find places the locals like to frequent.
Do you have a favorite place to suggest? Perhaps with melt- in- your- mouth calamari?

 

I don't remember names, but there are some upscale trendy restaurants (very modern, lighter, and sophisticated Greek/Mediterranean food) and bars in some nice residential areas near the center of the city where I've been taken by locals in the know. If you want touristic traditional, there are tons of little restaurants in the Plaka under the Acropolis. Another idea is to do a short day trip to the port of Piraeus (spelling?) for a fish meal.

 

Thanks for the tips. I like the idea of going to the port as that is something I haven't read about in the tourist books.

 

MikeMpls organized a small Athens DO last December. I know they were thinking about doing a day trip to the port, so he should be able to give you more information and suggestions.

 

Thanks MSPeconomist (wow, that handle is a HANDLE! )