I don't regret that we took a bus trip with lunch and a tour of Paris with time to view (but not enter) the Eiffel Tower. But it was quite expensive and lunch on the closed barge meant very limited views along the Seine. So use your time better and book a different tour or work out a plan ahead and do it on your own.
We were happy to have some time in Dublin even though the weather was grey and cool. Shuttle from the ship dropped us off near the center of the city. We walked around, did a little shopping at Marks and Spencer and had a Guiness in a pub. It would have been a good idea to get on one of the hop on/off buses at the beginning of the day but by the time we thought of that we didn't have enough time left to complete the tour which would take up to 4 hours. Maybe next time!
We really loved Liverpool! The ship docks right in the heart of the city and is served by lots of hop on/off tours which are very reasonably priced. Queen Elizabeth II was visiting the docks that day so security was evident around the port and the buses were a little diverted but still offered a great tour of Liverpool for only 5 pounds. We got dropped off the second time around near The Cavern Club and I was thrilled to visit the street where the Beatles got their start. We walked a lot, did some shopping and toured the Liverpool Museum on our way back to the ship. Museums are free so you can make a day of it and not spend much at all (except at Marks & Spencers and Debenham's and...)
We spent too much $$ on the ship's shuttle to the center of the city as they insisted there was no other option. But there were other shuttles at the pier (this was a tender port) and taxis too so feel free to venture out on your own. Edinburgh is a fabulous city and I wish we had more time there. The Royal Mile is an easy walk with lots of interesting shops and sites between these two landmarks. Prices for woolens and souvenirs (like Heather Gems jewelry) vary quite a bit so don't buy at the first store you see.