I'm not one that enjoys being herded like cattle on many of the ship offered excursions and much prefer to do it myself. There is lots of information and reviews online that document who the good tour operations are all around the world. I did my research and this is what we did on our port shops
1. Messina Sicily: my favorite stop of all, the beautiful island of Sicily. We hired Mario from SicilywithMario.com. He was absolutely fabulous, as his many reviews attest too (look him up on trip advisor). We opted to have just two of us, for a personal all day tour (200 Euros). He took us to Savoca, Castelmola and Taormina, as well as a tour of Messina and several short bonus stops. With the exception of Taormina--which is jam packed with tourist on port days--we were often by ourselves with our guide in some of the most fantastic scenery anywhere. He takes you places the tour buses cannot get to (and trust me, you don't want to drive yourself on those roads!!!). We enjoyed a fabulous lunch in Castelmola with a view of Mt Etna. This was our most expensive excursion, but well worth every penny.
2. Athens: we hired taxi driver Takis Kapoukakis and although he had a colleague show up to get us (can't remember his name)--he was very reliable. He was waiting for us as we got off the ship. Drove us to the Acropolis (pointed out land marks along the way), gave us a map with some general guidelines and agreed to meet us at the same spot at 3:00. We did our own tour of the Acropolis (there were maybe 20 people when we got there, so we basically had the place to ourselves before the tour buses arrived about an hour later). We walked around all the key sites, had lunch, finished at the Acropolis museum and then met our driver promptly at 3:00. He gave us a small tour of Piraeus on the way back. All that for a 50 Euro payment at the end--which I believe is significantly cheaper than those who negotiated for a taxi ride at the port--and much more reliable.
bigger than our hotel room in rome. Loved the balcony