If you only have a couple of days in Paris do the Open Top Bus Tours

There are a couple of Companies that do Bus tours of Paris I think...or maybe only one but it doesn't really matter as they are mostly the same. These are the fastest and best ways to see all Paris has to offer. You can jump on and off and different stops and your ticket is valid for 24hours so if you buy the ticket at 3pm it will be valid till 3pm the next day.

You will see all the major attractions including The Eiffel Tower, The Louvre Museum, Notredame, Champs-Élysées etc etc

You can get tickets from the bus drivers and there are stops all around Paris so just ask at your hotel or anywhere really. If it is winter take warm clothing so you can still sit on top and if it is Summer take sunscreen as Paris sun still has some burn capacity. If you have never done an open bus tour know you get a disposable pair of headphones which you plug in next to your seat and you can listen to a commentary in your local language.

NOTE - The Paris Louvre Museum is closed on Tuesdays so don't go to Paris expecting to get into the Louvre Museum on Tuesdays.