Let me add my view here
- Sofitel Legend : Agreed with Kaizen7. Superb historical hotels
- Sofitel : a lot of great properties. A few "average", but overall, always pleasant
- Pullman : great brand. Business-oriented
- MGallery : one of the best brand/asset of Accor IMHO. Great hotel experiences.
- Novotel: well...I need a whole box of Prozac when staying at the typical Novotel rooms while I truly enjoy staying at "new" (Novotel London Canary Wharf) or recently renovated ones (Novotel Edinburgh centre - see my recent review).
- Mercure : old not renovated can be horrible but new or renovated ones can be just great. Plenty of Mercure are way better than most Novotels
- Ibis : standardized but does the job. I like the Ibis Style brand (limited experience for me but 100% satisfaction)