Well, some of my favorite travel memories are of iconic places that everyone visits. I can honestly say I have not been disappointed in any place we have visited, and have been pleasantly surprised by a few. So I will mention some favorite places/memories here:
2012 - our first visit to Paris. Oh, what a gorgeous city! It was everything and more I hoped it would be. A highlight was watching the Eiffel Tower light up at night while having a picnic on the grounds below. Just magical! Another highlight was climbing to the top of the Notre Dame tower and seeing the gargoyles up close and personal, along with stunning views of Paris.
2013 - Our oldest daughter lives in Provence with her French husband so we have visited many times. During a trip in 2013, we visited Cassis. Then we attempted to drive the road on the cliffs overlooking the Mediterranean (Route des Cretes). We stopped at the first lookout point to take some photos. OMG!!! I couldn't make my way around the car door because the winds were so strong! My daughter and husband crawled on the ground to a spot where they could take some photos, and then crawled back. Then we proceeded to drive further up (how stupid of us), but the police came and told us to turn around because they were closing the road. It was too dangerous because of the winds!
2017 - Andalucia, Spain. I have wanted to visit Andalucia for years and years, and we finally went in September 2017. I loved everything we saw! The highlight for me, no surprise, I am sure, is the Alhambra! I couldn't believe I was actually there. It is beautiful and awesome and one of the most remarkable places I have seen. And the Alcazar in Sevilla!!! Just as stunning as the Alhambra, a very close second for me.
2018 - Lisbon, Portugal - we loved everything about Lisbon, but I think our favorite day was the day we spent visiting the Sao Jorge castle, and then slowly wandering through the Alfama. I had read the Alfama is very touristy, but to our surprise, that is really not true. Yes, there are gift shops & cafes close to the castle, but once you get away from the castle, it was not crowded or touristy at all. We loved the narrow up and down streets and alleyways, the stairs, clothes hanging from balconies, open windows with music playing. We sort of followed Rick's walking tour of the Alfama, got lost quite a bit, but it was fun!
And a more recent memory in September 2019 when we visited Croatia and Slovenia: We rent a car for a day while staying in Ljubljana to drive to Lake Bled. We followed the route that Andrew Hall on this forum recommended. The route took us through Skofia Loka, Jamnik and Kropa, to name a few. We drove through spectacular scenery with mountains, valleys, small villages, churches, and grazing sheep, cows and horses. And everything was so green! Lots of switchbacks! I kept saying WOW at every turn!