I'll try to restrict my list to the {5'6" to 7'6"} range, from those I like the most to those I like less and less. Multiple models occupy the same rank if they are "close enough" that I cannot really say one is definitely better than the other(s):
1. {Fazioli F228} This is a class by itself.
2. {Steinway B, Kawai RX-A, Shigeru SK-6}
3. {Mason and Hamlin BB, Fazioli F212, Shigeru SK-5, AugustForester 190, some Bosendorfers, Yamaha S6}
4. {Pleyel 190, Estonia 190, some C.Bechstein, a Baldwin SF-10}
5. {Steinway M, Yamaha C5/C6, Kawai RX-5, Estonia 170, Pleyel 170, some other C.Bechstein, Yamaha C7, Shigeru SK-3, MasonHamlin A}
6. {Petrof II, some other Bosendorfers, some of the bigger Schimmels}
7. {Petrof III, Schimmel-VOGEL, yet some other Bosendorfers}
8. {Some other Schimmels, Petrof IV, Yamaha C3}
9. {Grotrian 6'3", yet some other Schimmels, the larger Knabes and YoungChangs/Prambergers, Kawai RX-2/RX-3}
10. {Yamaha C2, smaller Knabes, smaller YoungChangs/Prambergers, Schulze Pollmans, Samicks}
Bosendorfers, Schimmels, and Young Changs float all over the place because, well, I don't remember the exact lengths of the models I played -- I just have the impression that there are some Bosendorfers/Schimmels/YoungChangs models that appealed to me more than the other models from the same manufacturers, or just different instruments of the same model. They just span over a wide range of quality and tone colors, some I like, some I don't. (I could say the same for a lot of Steinways I came across lately, but in the above ranking I used the Model M and B I like the most.)