Do you like art? Do you like history? Do you like bones? I've been taking groups to Paris for six years now, and it is hard to go wrong with any of the main attractions. In two and a half days, we do:
Top of the Eiffel Tower
Top of Arc de Triomphe
Sacre Couer
Notre Dame
Latin Quarter
Louvre
Versailles
Catacombs
(high energy group, or maybe crazy tour director, but nobody complains!)
sometimes Pantheon
sometimes Invalides
sometimes Carnavalet (fits well with a visit to the Jewish Quarter for lunch)
Food is easy to find - you don't need to seek out certain restaurants. If you want to try something specific, such as the best falafel you'll ever eat (Jewish Quarter), then do your research beforehand and make that part of your plan for the day. If you want a decent meal, large portion, quick and easy, try some of the self serve restaurants (Monte Carlo half block down Champs Elysee from Arc De Triomphe is always filled with locals / Rivoli.fr on Rue de Rivoli right across from Tuileries(near Louvre)has more tour groups than locals, but very good cheap food - not great ambience though!)
Have fun.