Four Seasons, I agree, is the obvious choice.

I'd like to throw Como Hotels (www.como.bz) into consideration too, though - while they're certainly not anything like the size of Four Seasons, in many of the markets which the two groups share, Como's properties (in my opinion) surpass Four Seasons. (I'd choose the Met Bangkok over the FS, for example, and the Como Estate in Bali over the FS Sayan.)