Best port by far... what a beautiful city, we actually want to go back and possibly buy a condo there... watch out Miami Beach! Cartagena can give you a run for your money ;)
Our tour included the San Felipe fortress, the Cathedral, the Bovedas, the walls walking tour, the inquisition palace, and the beach... great value for our money.
Nothing to see in Colon, definitely worth to take a tour to the jungle or Panama City... some of our friends took other tours and were not impressed though, most people said the railway tour was a huge disappointment.
Our tour included the best of Panama City, it was very good value for our money, definitely recommend.
Colon: not at all... very dirty and ugly; and shopping was pretty bad for a free port, we wanted to buy a Panasonic waterproof hybrid camera ($169 at Best Buy in the US); it was $399 in Colon, forget it!
Didn't take an excursion since Machu Picchu was so overpriced... just took a cab downtown and the shuttle service from Miraflores back to the ship.
Lima was very nice and pleasant to walk around, although you must watch for pickpockets; the historic centre is beautiful. They charge US$10 to enter the Cathedral, what the...?
Our tour included Valparaiso and Viña del Mar, although it would have been better to include more of Santiago or the country side (the wineries)... not much to see in Valparaiso and Viña, rather dirty and not resort-like at all; don't expect Miami Beach/Cartagena/Cancun, the coastal cities in Chile (and the beaches) are not as nice.
The tour ended at the airport, that was so convenient! the lunch at a local vineyard was awesome, great food and amazing landscapes; overall, great value for our money.