We came by car from Romania, stayed 3 nights in Parga, 3 nights in Kefalonia and a week in Zakynthos. It was our first time in
Zakynthos and we were trully happy to see such a wonderful island! Zakynthos is obviously more crowded than Kefalonia and more organized. There were places that were exclusively for tourists. For example, Laganas.
Tourists in Laganas in summer are certainly more than the locals. This is a resort only for tourists, with big hotels and international restaurants. I was wodnering, why people need international cuisine in Greece, don't they come to try the local recipes and gyros? The only good in Laganas was the boat trip to the turtles and Marathonisi. The beach was nice but you can find so many other beautiful beaches in Zakynthos and less crowded.
A must is a boat trip to the Blue Caves and Navagio. Also rent a car for a couple of days and drive all the way from South to North West. Stop wherever you want and enjoy. The coasts of Zakynthos are gorgeous but so is the inland with all those lovely villages in the mountains.