Portofino was absolutely stunning. We took a 2-3 hour hike into the hills surrounding Portofino which gave us breathtaking views of the coastline. We ened up at San Frutuoso Abbey, which is a gothic abbey (c. 1255) that can only be reached by boat or on foot. Had lunch there overlooking the ocean and then took the local ferry back to Portofino before returning to our ship. If you are someone physically active you would enjoy doing this!
Monte Carlo was pretty and there was a lot of conspicuous consumption to be seen. Walked up to the Royal Palace for nice views of the harbour and then walked to the casino. While it was opulent it wasn't my favourite port on our cruise...but we prefer the quainter ports such as Portofino, Sorrento and Koper.
We didn't actually get to spend very much time in Sorrento as we hired a local limo driver to take us up the Amalfi Coast Drive. We would highly recommend this as the views were just spectacular. We stopped in Positano and then had lunch at a hotel our driver recommended - Calajanara Restaurant, which was right on the cliff overlooking the coastline. Brilliant views and great food. We ended up in Ravello which was a quaint little village. It was a full day tour with numerous stops along the way for picture taking. Made us realize that someday we would like to go back to the Italian coastline and spend more time looking around.