If cost was not a factor (I can get a corporate rate that is about equivalent at these three hotels), which would you choose for a first-time visit to Philly?

If you are just interested in lounging in luxury, go for the 4 Seasons. If you want a more convenient location for shops and restaurants go for the Rittenhouse.

Thanks! So if I don't mind walking a bit farther to get to things, 4 Seasons is a nicer hotel for the $$$? My impression is that the Rittenhouse has larger rooms but somewhat shabbier, though still very nice. Is the Sofitel in a different class altogether?

I live in Philadelphia. My sister was here for a visit last week and stayed at the Sofitel. It is a wonderful modern hotel in an excellent location. The Four Seasons is also lovely, but not as centeral as the Sofitel. I believe the Sofitel is #1 rated in Philadelphia according to Trip Advisor.

Yes, the Sofitel gets excellent reviews on Trip Advisor so I will definitely consider it. I get a corporate discount at the Rittenhouse ($250) and Four Seasons ($220), and the web rate for the Sofitel is $195. Convenience to sights and restaurants is a consideration but the hotel itself is probably more important as I enjoy walking around a city...and being pampered! Thanks for your help.

Four Seasons for luxury and museums.
Sofitel for Walnut Street shopping.
Rittenhouse for the park - skip the hotel.

I stayed at the Sofitel in 2005 and found it an excellent base for exploring nearby Rittenhouse Square and the top shopping and restaurants near it. In general, I think it would be a much better choice for city walking than the Four Seasons, which as noted above is less centrally located, although a better choice if your main focus were the Philadelphia Museum of Art and Rodin Museum.

The Sofitel is strikingly different from your typical American luxury hotel--largely French staff, many French guests, decor that is very modernistic, even avant garde. I enjoyed it.