Two ideas, both including dinner (or lunch).
Le Ciel du Paris - the restaurant at the top of the Montparnasse Tower. Fabulous view, including the Eiffel Tower. Dedicated elevator at no additional cost and no long line. Good food.
Le Calife - dinner cruise on the Seine. This is the only one where food is prepared on board, and it is quite good. The dinner cruise is timed to coincide with the Eiffel Tower's twinkling.
Both have a selection of menu plans with a variety of price levels, and we had good window seats at both even though we didn't choose the most expensive option. You can make reservations and see their menu on their websites. Le Calife has a reservation window starting 30 days prior to your desired date, and you do have to pre-order your menu selections.
IMO both provide a memorable experience and are good value.