Mmmm, Paris.
The people I've met who had rude experiences in Paris were people who didn't try to learn a lick of French. Not even "thank you". Do either of you speak French? I had all wonderful experiences there- and feel when traveling to countries it's important to at least learn the polite words: thank you, your welcome, please, I would like (as in when ordering food/beverages), yes, no and of course "where is the bathroom?". Being familiar with numbers also helps a lot. They will usually speak to you in English anyway- but just making the effort seems to go a long way towards good will. :)
In Paris I stayed in a tiny B&B near Sacre Coeur, which was beautiful. It's in Montmontre- considered the historic artist section of town. Part of that is really commercial now, though. en.wikipedia.org/wiki/Basi..._C%C5%93ur I recommend a visit to Sacre Coeur.
Just walking around Paris will be beautiful in the springtime. Notre Dame is a must. A fantastic day trip is Versaille. Really amazing. The Louvre if you have time.
I had a car when there and also went to Giverny- the gardens of Monet- which he considered his "greatest masterpiece". That was nice. Etretat was AMAZING. Le havre, Honfleur and Mont st Michele also incredible. Some of those might be a day trip out via public transportation, but I'm not sure. One of my favorite places was a tiny dark little medieval village- I'd have to look in my album to remember the name. I felt like I stepped into the set of Willow for some reason, even though it looked nothing like it.
ANYWAY... just as important as where to go is dear lord what to eat. Holy crap YUM!
MUST HAVES: crepes. I'm veg- so always got ones with cheese and often egg. I didn't try the dinner kind from the street vendors- only at restaurants. Get the savory ones with buckwheat flour. REALLY good! Of course sweet crepes with Nutella are also a fantastic choice. They sell 'em all over in little street stands, including right by the bottom of the Eiffel Tower.
There are over 400 different kinds of cheeses in France. They know their cheese! Pont Levec is one of my favorites over there (but not so good over here). The soft cheese are my fave- mild, creamy and rich.
Caramels. They melt in your mouth and are totally different from the plasticy ones over here.
Chocolate with liquor in them- brandy especially. Really really good.
Pomme Frites (French Fries) from the roadside stands are really good.
You'll wanna walk around everywhere just to walk off the food! :) Wear comfy shoes.
There are tiny groceries and markets all over. We would do lunch by getting bread, cheese, tomato and maybe something else and just picnic in a park.
The metro is really good though to get you in the general vicinity of things. Watch your belongings of course.

We are going to miss eachother by days!! I'm in Barcelona for a week- until April 30th... then I'm in Paris after that. Damn! It's pretty cool that we will both be adventuring across the world at the same time. Hope your trip is fantastic.