Funchal, Madeira was lovely and easy to do yourself though it is a bit of hike from the ship into town so we paid the $10 shuttle bus fare. We then took the cable car up to Monte and a separate cable car down to the Botanic Gardens (Euro 15 return including entry to the gardens). We paid Euro 45 for three of us in the Toboggan down from Monte but to be honest it was a big disappointment and a waste of money; I would not bother if I were you! We then got the public bus back into Funchal, which cost Euro 1.25 each as we had bought tickets at a booth in the town, otherwise it would have been 1.90 each. The taxis were charging Euro 8 back to town. If you're not doing the Toboggan then you are better getting a return ticket on the main Cable Car.
Santa Cruz de Tenerife was okay; the port authority provided a free shuttle bus which cut out a long walk and from the drop off point the town was very walkable with plenty of interesting architecture, parks and shopping areas if you bother to go beyond the immediate area of the drop off point and main shopping street.
The port of Puerto Del Rosario in Fuerteventura has little to see other than a pleasant old church and some nice sculptures; there was also a small market on the promenade but it only took about an hour to see everything. We then headed to the bus station and took the Bus No. 6 (Euro 3.10 each way) to the Northern beach town of Corralejo that offers fine views of Lanzarote and Isla de los Lobos, as well as having a decent array of restaurants on the promenade and in town. The bus leaves every hour, on the hour from both Corralejo and Puerto Del Rosario.
The port in Lanzarote is around 2 to 3 miles from the town of Arrecife and for part of the walk there is no pavement so I suggest you pay the $12 for the Celebrity shuttle bus that drops you off on the edge of town. On leaving the bus turn left and walk into town; it is worth walking along the entire promenade including walking the harbour walls then once you complete the promenade walk turn back on yourself and turn left into Calle Lyon Y Castillo that is the main shopping promenade, full of perfume and cosmetic shops (heavily discounted to the point of being cheaper than the duty free onboard).
Lisbon is a great capital city with so much to see and do. Use the Yellow Hop On-Hop Off bus for Euro 15 each because it includes a tram that takes you up to Alfama, which the Red Bus does not include. Be sure to use the bus to visit Belem for the Monastery, Belem Tower and Monument to the Discoveries. We were lucky as our ship moored across the street from both the Yellow and Red Hop On-Hop Off buses; if your ship moors further down river, you may have to use the ships shuttle first.