This tread confirms exactly why most of us don't just belong to one hotel chain. We went to France last year for 10 days and spent time in Paris, Cannes and Nice. Hotel stays were split between 3 hotel chains as follows and only one of the stays (the most unremarkable of the three) was with Starwood even though I'm a big Starwood fan.

Paris - Radisson Blu Champs Elysees
Cannes - Intercontinental Carlton
Nice - Le Meridien Nice.

Spain was a different story this year with Starwood getting 7 out of 10 nights. Next years trip to Greece will be heavy on the Starwood side as well since most of the other hotel chains only have properties in Athens.

OP...I would take a look at Club Carlson for France. Picking up their Visa card could be a good way to go especially if you plan on staying in several areas for just 2-3 nights.