Seine river cruises

Undoubtably, Ducasse sur Seine:

https://www.ducasse-seine.com/en

We just went down to the Eiffel Tower area, got our tickets and hopped on. It was nice to just sit and relax and watch the sights (we didn't do a food one, just a plain cruise). They have some drinks on board you can buy, probably overpriced, but we forgot to bring water :)
If we manage to get back to Paris will definitely think about an evening one
This article explains how to read the signage; the photo is the signage for RER B from CDG to Paris city center; but the idea is similar for the other direction.
https://francetravelplanner.com/go/paris/trans/air/choose_train.html /shaglevoojio

We don't eat on local cruises -- learned that lesson decades ago so I'd do the cruise and book a nice restaurant on land. BUT if you want to cruise and eat Tocard's recommendation is best and Calife also has a lot of fans and while not cheap is I think a bit less pricey than Ducasse.

The best value for money of the day pass on Batobus.

If you just want to discover the main landmarks on a one-off cruise, Bateaux mouches, Bateaux parisiens and Vedettes de Paris are almost equivalent and their only difference is which part of the city you are boarding.

Food is average, you would have a better meal on a café/bistrot. Unless you want to pay for a cruise with a chef (much more expensive).

Batobus with your picnic from a boulangerie-patisserie. The one- & especially two-day passes are great deals, & the itinerary goes from the Eiffel Tower to four-five stops along the Left Bank to Jardin des Plantes, then back along the Right with four-five more. Frequent boats all day.

Anything with the name Alain Ducasse attached to it must be fancy :)
I love his chocolates, one of my favorites!

Agree with Janet. Eat elsewhere, and enjoy the sights and the ride.

We had a wonderful dinner and tour on Le Calife when we were there for Christmas a few years ago. It’s a beautiful older boat, and it’s small, so feels intimate. The food was delicious. A highlight of our trip!