One of the great cities of Europe. Definitely get on the hop on-hop off red, double decker bus. Really inexpensive way to see everything. Then you can decide what you want to go back to if you have the time.
An incredibly interesting walled city. It's been mostly rebuilt after the shelling and bombing suffered in the 1990ish war. (Sadly, the roofs are all bright orange/red instead of the weathered tile.) Still, it's an incredible city. Wife and I hired a taxi. He took us from the ship to the top of the mountain where the cable cars end up. He gave us an explanation of the town, the war, etc. He'd stop frequently for photo ops. Then he left us off at the main gate to the city. It was Euro 50. He said it would be an hour. It ended up closer to two hours. (Not complaining, just saying we got our money's worth.) I think a taxi to town and a trip for two on the cable car would have been around Euro 40, so I'd definately recommend this option. With the map provided by HA and Tom's talk (in person or on the TV), you really don't need an excursion. This city was the highlight of our cruise
We've been to Venice many times. It used to be one of our favorite cities. But it now has WAY too many visitors during the daytime. And the people have become disenchanted and rude to the tourists from whom they make their living. The nicest people we met were from Sengal -- selling fake designer purses and watches. They were polite and fun to bargain with. And for God's sake, don't pay their asking price. They asked for 60-75 euro for a knock-off designer purse. We bought the first one for 20, second for 15, third for 13. It was fun bargaining with them. Just keep smiling and saying, "No, I'll get it somewhere else." Anyway, the only reason I give Venice a 3 is that the city itself is incredible and should be experienced. But it's like the Acropolis: way too crowded for a repeat visit. USA today even did a recent story on the need for a limit to tourists per day.