We embarked at Barcelona. Very big city, nice buildings, easy to get around. We got a taxi from centre to port which was about 15 euros plus tip. Our taxi back to our hotel which was further away was 30 euros (incl small tip). It's about the same to the airport direct.
We have been to Barcelona quite a few times - Las Ramblas is a huge shopping area with MIMES on the street - quite incredible some of them. Eating on Las Ramblas is expensive so go down a "side" road or elsewhere.
Got off a cruise ship before in Naples and did suppossedly a "panoramic view coach trip" - was overpriced, and we both thought Naples (See Naples and Die - they say) was very over-rated. On this little excursion we saw a "first" coffee house and pizza shop (which were closed and nothing at all special). The Opera hall closeby - old building (probably famous) but we have seen much bigger/decorative/nicer elsewhere in England.