Flying into Paris for a 2 day stay and then leaving for Wales. I realize that much more time is needed.... but if you were only staying in Paris 2 full days.... what would you do to have the best possible experience?
What sorts of things do you enjoy - museums? Parks?
For this sort of visit, you need to ask yourself what YOUR idea of Paris is. Is it seeing the Eiffel Tower? Shopping? Dining well?
I'd pick two of the big sites to visit, unless you're okay with just walking past, in which case you can probably do 4 or even 5 if you keep moving.
If you want to eat on the fly, that's fine. But if you want to eat well, you'll need recommendations and reservations. For shopping you'll need recommendations for areas or stores as well.
Tell us what you want.
what would you do to have the best possible experience?
For me it would be art and architecture:
First morning at Musee d'Orsay. Afternoon Seine cruise. Dinner in Montmarte after seeing the Sacre-Coeur.
Then Sainte-Chapell, check-in on Notre-Dame's progress and walk to the Louvre. Then a trip up the Tour Eiffel just before sunset. (This day may be a bit rushed due to sunset time. If so, the Louvre is probably out unless you want to see just a couple of rooms).