hop-on-hop-off buses in Paris

They are a terrible way to get around and useless as transportation. A non stop bus tour is a better idea, HOHOs are all about waiting endlessly. Especially if your time is limited don't waste it that way.

We took one and while it was a good way to get oriented, we only got off at one stop and regretted it because we had to wait a long time for a bus with room on it, to get back on. So we just didnt get off again and made the whole roundtrip. I cant see you could get off at more than two or three stops and actually see anything. The guided information on the bus wasn't much, as we spent a lot of time in traffic. And the bus is just transportation, not tour guides at any of the stops. I dont remember Sacre Couer or Montmartre on the route.

So, to actually visit the sights, I think you'd be better off using the metro. For orientation it was good.

I agree about HOHO buses in general, only useful if you don't mind sitting there watching traffic, punctuated by iconic buildings and views. Not a good plan if you really want to hop on and off.

From Orsay to Tuileries to Champs to Eiffel could be done on foot, maybe with a couple of breaks. If you don't want to brave the Metro to get to Montmartre, a taxi would work -- take it up to Sacre Coeur or Place du Tertre, enjoy the view, then walk down through the streets.

I like the Batobus hoho cruise boats on the Sienne

hey hey lisa
not a good idea, you'll be caught in traffic without moving far. plus long waits at stop to get back on.
couple other ideas to ponder about:
2cvparistour,com
check the tours available, what places and attractions you see. montmarte is also on the list
oldtimersparis.com
retro paris tour of the attractions
tuktukinparis.com
click "our tours" and look what the offer
tuktukride.com
click tours to see all they offer
lapetitefrenchieparis.com
check out what they offer
retro-tour.com
check the fun tours on this sidecar.
cedricsparis.com
take a look at the tours, donates to orphans of firefighters, discount for firefighter and bring a patch of your local fire station.
we took a cv2 tour in reims, champagne region. it was a fun day, then stopping at cafe du palais for flights of the local house champagnes, then train back to paris.
anyone you book with, tell them you want a stop at montmarte (place du tertre), "I Love You" wall. email them and get more answers and knowing exactly what and how much. some offer wine or champagne extra charge. you're gonna have a lot of fun, been 4X, so much to see, do and eat. one year did a best eclair hunt for me and best french onion soup find. had to eat souffles so went to la cuisine de philippe behind luxembourg gardens, was yummy.
aloha