To my knowledge there are 5 taverna’s in Selia, so I guess it depends on what you want.
As MickyDripping said Elia`s run by Nickos is good, quite upmarket, but good food although I thought a little expensive, you then have Menastri which has the same views as Elia`s and is run by Yogos and Annie a brother and sister, they serve modern Greek food with a twist.
On the way out of Selia towards Rodakino you have another Taverna owned by Nicos I can’t remember the taverners name but it has large glass windows and is on the right just as you get to the end of Selia, Nicos has been a chief in and around Plakias for the last 25 years and his menu is a bit less adventurous and more traditional and his prices reflect this.
Then again I can’t remember the name but there is a taverna on the lower road as if you were going to the cheese factory again this is very traditional and mainly barbequed traditional meats and dishes, I have only been once but it was OK.
Then there is the one in the centre opposite Elia`s, I have been a few times good basic food with prices to match.
So Take you pick and bon-appetite