We had a wonderful intro to Paris via the Sights of the Seine tour. Our guide Hanna, though only her first full tour with Sight Seekers Delight, was enthusiastic, entertaining and informative. The script on the tour was a nice blend of historical and current points of interest. Wish we had more time to do the Montmarte tour, hopefully next time.
A word of advise is that the tour is fairly rigorous in that we walked about 3.5 hours straght with 30 min break for lunch. so probably not for everyone. However, if you can do it I think it is a much better way to see the sights than from a boat. A good value as well. Hightly recommended.