We went to Sappho a few weeks ago. The atmosphere there was great, authentic and homely.
The food was amazing. There isn't a menu as such you are just asked if you are vegetarian or not and once you've answered this just sit back and wait for the food to come...and it just keeps coming! The waiter/owner (?) we met with was helpful and courteous. Good local beers available.
Be sure to have cash as I don't think they take credit cards. I think we paid up to £30 for 2 beers and meze dinner for two.