I was in Paris for one night (about 30 hours total) in March. A good way of seeing a fair bit is getting the metro to Chatelet - walk over to Cite and see the Notre Dame. Head back towards Chatelet along the Seine, taking in the Louvre. Then, head towards Place de la Concorde, onto the Champs Elysee, to the Arc de Triomphe. You'll also see the Eiffel Tower wherever you are. That's probably a 2.5 hour walk, taking in the main sights.
12/4/11 at 6:10am