Every option the research turned up, ranked best-first and folded by category. Tap a category to open it, then mark who is keen so you can find your overlaps.
Everyone's picks are saved to one shared list, so all three of you see the same thing no matter whose phone you are on. Just tap your initial (D, M, or C) on anything that appeals and it saves for the group automatically.
Open this on one screen together, or each on your own phone. Changes from the others show up within a few seconds. The Copy and Merge buttons are still there as a backup if you are ever offline.
The ranking (the gold dots) blends four things: uniqueness (can you only do it here), quality (how good and well-run), ease (access, booking, transfer), and value. Five dots is a standout, three is a solid option if you have time. In the plan means it is already in the recommended itinerary; Optional is an extra to consider.