The PPQ probably has the best trigger on a striker-fired polymer pistol to date, but it's in a different size envelope than the other two. PPQ is a service-sized semi, while both the SR9c and M&P9c are compact models.
A PPQc would sell like hotcakes, I think.
The Walther P99AS actually has a better-feeling trigger than the PPQ (the AS trigger is ever so slightly lighter and crisper than the PPQ trigger, with the same incredible reset), and it is available in a compact size - the P99c AS. It's about the same size as a Glock 26, and can take full-size P99/PPQ mags.