It is a rather thin field -- domestic sedans under $25k. The Big 3 have been focused largely on other segments, leaving even the newer products to trail import competition in execution, like the Chrysler Sebring.
I agree, the Ford Fusion and its siblings definitely stand out. Nice size, entertaining dynamics, clean execution. Available in AWD is a key distinguishing factor.
The new Malibu looks promising, though my expectations are tempered by experience with the Aura.