I'm not sure if it is because I am a photographer, but I "see" my memories as pictures in my mind. When I am suggesting Things to do in Paris to family and friends, I choose from the images (in my head) that made a lasting impression on me.
A favorite is the view from the top of the glass-enclosed escalator on the Centre Pompidou, which houses the Museum of Modern Art. You'll want to go to the Panoramic Terrace at Level 6 and ride all the way down. The escalators descend down the outside of the building in a series of glass tubes. Very modern and very cool. I've noticed that a lot of couples think that this "ride" is a great place to kiss, and why not? After all, they are in Paris!
In the clearest panel in the middle of this photo you can see Basilica Sacre Coeur high on the hill overlooking Paris. The view is gorgeous!
I am not a big fan of modern art (I distinctly remember seeing an all white exhibit that, as you approached to view the texture, you could hear whispers in French being piped in surround sound - neat, but a little unnerving!), but everyone should see a Warhol in their lifetime. Open your mind, wander through some unexpected exhibits and then ride down the glass great escalator. This is what brings delight in Paris.