What are some really great things that shouldn't be missed in Paris?

A1:
Go to the Louvre, see the famous Mona Lisa, just cause it's Paris.
The cafes are really nice, you can find a lot of nice ones.
RESTAURANTS- need to visit and experience. Plenty of ones to go to and brag to your friends about.
SHOPPING/browsing the original big name stores that you can't find in America.
I'll add more when I remember what else.(:
EDIT: I didn't really go to the shadier parts I went to the really highclass shopping amazing restaurants part
AND check out the Flea Markets and Jazz club thingys-AMAZING to go to

A2:
for nightlife you must pass a night at Lido nightclub.
Take a ferry-tour on the Seine River
Visit euro Disney
Walking in Champ-elisee and enjoy time in its cafes
Paris is fantastic City, you will enjoy each minutes there

A3:
the place du tertre is a square where artists paint outside all day. it's right behind the sacre coeur cathedral on top on montmartre. at the bottom of that hill is pigalle and the moulin rouge. also the catacombes, the jardin du luxembourg, there is a cafe on the bastille roundabout called cafe des phares and every sunday morning at 11 they have philosophy debates. the centre pompidou is the cool modern art museum, and some of the cathedrals not as famous as notre dame but still very pretty are the madelaine, and st germain. try to make it to versaille too.
shady sections are mostly the suburbs, the ritzy sections are the champs elysee, most of the center, and the 16th...