In Lassi behind Argostoli the long and wide glass. Nice water but gathers people.
In Lourdata you go from Argostoli to Poros. Great beach, quiet but with very fine sand.
Generally, all the southern beaches are so but there rather than fine. One of them is in Scala.
Where to go, there are good fish taverns in Katelios.
1) An anime, nice beach in the green with pebbles. It's nicer for a breakfast-lunchtime bath as the sun sees it. Afterwards, go to Agia Efimia to eat in the taverns that are on a hill above the sea.
2) Petans, reminds a bit of Myrto but more beautiful in my opinion. Myrto liked me only from above.
3) Any visit to Ace
4) On the side of Lixouri you can go to Xi and Vatsa at the cave tavern that is on the sand.
5) The Old Plaka in the port of Argostoli is a nice food and cooked.
Go and stroll to the lighthouse of Argostoli in the afternoon when the sun falls when you are a romantic guy
6) Visit to Lake Melissani at 12 at midday when the sun is over the hole of the cave.
What you said, I think it's all the money on the island. A good choice of accommodation because it has its own life and certainly the most "central" point for the excursions to which you should be armed with patience because the distances are enormous and at the same time with great care because the roads were (I do not know they are) miserable
Petani, Xi, Antisamos, Myrto the best beaches. The latter, although more famous, must make a vow to succeed without a wave and find yourself parked. 2 Girls (Longs-Plates), good enough (if I remember someone I liked most) with enough people and beach bars
Assos is by far the most picturesque village, Fiskardo, the most beautiful for laziness and afternoon food. Agia Efimia also very nice family with many dining options. I liked the evening.
As for Melissani and Ag. Gerasimos is worth visiting ...
ALEX will tell you more about the parts.
My advice if you want to see the island is to split the map into 4 (NW, NW, ND, NA) because otherwise it will take you miles.