A couple more things: This may seem obvious, but organize the sites by area, rather than priority, to minimize travel/metro time. (With the museum card you can hit lots of lesser known sites, sometimes finding gems.

Save the cruise for when your feet hurt and you aren't motivated to go anywhere (that really may happen a few days in). It is not a necessity, but it is an enjoyable diversion whether during the day or at night. (Very different if dark versus light, but both are neat).

I love museums, but can't imagine doing the Louvre and the Orsay on the same day. If you aren't a big museum person, I would skip the Orsay, much as I love it. Would one of the smaller museums, such as the Rodin or the Cluny, interest you?

I totally agree about adding Saint Chapelle.
I've been to Paris 5 times, and it is still a must see each trip. Note that they were doing major restoration work in there in May, and at least a third of the windows were covered over. Still stunning though.

Also, I've stayed near the Rue Cler twice and enjoy the area, but "walking it" will not take a lot of time. It's fairly limited, and there are better market streets.

Thank you EVERYONE for taking the time to give me so many amazing advices and opinions!! I will take a little time to review each of your suggestions, and get back with a new day to day itinerary

Agree with Mare...D'Orsay and The Louvre are too much on the same day. I also would recommend Ste Chapelle. However, depending on the art you want to see...I would skip the Louvre and see D'Orsay. (but I much prefer the art at D'Orsay).. Another option, might be to include the Louvre and visit L'Orangerie instead of D'Orsay. The huge Monet canvases at l'Orangerie are magnificent. It is much smaller and less crowded museum. I do love Rodin museum, as well. Opera Garnier is one of the most beautiful buildings anywhere and worth a visit.I also think that St Denis is under appreciated.

I think the view of the Champs Élysées from place de la Concorde is lovely...however, for me, a walk down the CE is crowded as hell. Disappointing (again, for me), very touristy and loaded with essentially every store you would see at home. I understand wanting to do it...but I wouldn't lose time walking it when there are other sites to see. You decide ultimately, just a "for what it's worth".

I would also agree that rue Cler is OK but not a great market street. If you are up for a stroll somewhere, Promenade Plantee is lovely. (it is right by Opera Bastille).

I also continue to learn that you can't see it all...I still haven't so I always will have a reason to go back.
Good luck with the planning and enjoy your trip.

denisea...

I will add a very enthusiastic agreement that St. Denis is underappreciated...I actually prefer it to Notre Dame...not as majestic (or packed with tourists), but I think it is incredibly mystical (as a gothic church ought to be).

It's my favorite tip for anyone looking for something he/she hadn't done before in Paris...so I'll temper my comment by saying maybe it's not for a newbie with only 4 days, especially since it takes about a half hour to get to by Metro...but I love it.

SS

For the view of the Champs from the Arc to Concorde, take the city bus!! It's a great sightseeing ride.

Yeah, I know St Denis is not really a short trip destination. It is a bit of a haul on the Metro, but I am always wanting to share St Denis with more people. I totally agree with you. I find Notre Dame so impressive outside but less so inside. (Although the view from the towers and all those gargoyles are wonderful.)

Denisea...

The best time we ever visited Notre Dame was early Sunday morning during mass. My wife and I were taking a morning walk killing time before our planned museum would open (can't remember which one -- and there really is no such thing as killing time on a beautiful Paris morning ), and on the spur of the moment, we decided to pop in. (Our hotel, Hotel de Nice, is only a few blocks from Notre Dame).

The worship area was closed to tourists (so there were only a few dozen or so), but we still could walk around the outer areas and see and hear the service, and the atmosphere was amazingly spiritual -- and we are not Catholic.

SS

I would also recommend the canal boat tour in Bruges. We enjoyed it very much.

Paris is a great city for walking. But its not much fun if its raining a lot, and you can get rain in September. So, consider how you would want to spend your day it is raining too hard to walk around without getting soaked. I have been in Paris when it has poured for days.

You may want to consider a museum pass ..it includes admissions to many sites and monuments as well as museums..but if you are under 26 and an EU citizen, museums and monuments in France are free.. you need to show some type of proof of age an EU citizenship .. dont buy a museum pass if you fall into this category
also if you are under 26 an EU citizens and you decide to go to Versailles, you dont have to pay for the general admission, and you can get a pass there so you wont have to stand in line .