Recoil is hard to quantify. As others have mentioned upthread, lighter pistols generally tend to recoil more--it's the whole "equal and opposite reaction" thing. But there's more to it than that--higher bore axis can amplify recoil by exaggerating muzzle flip (there's more of a lever effect for the recoil forces). Grip angle can affect recoil--a steeper angle means the recoil pushes back into the wrist more, and will tend to minimize flip. A heavier slide can add to recoil since it's a large rapidly reciprocating mass. Action types (blowback/gas retarded/Browning locked breech) can also change the feel. Even how someone grips a pistol also affects it.
Finally, there's personal perception. Some of the pistols mentioned above by others as having more recoil (the USP and P7) I find quite mild. For me, I've always felt that the Glock 17 had the sharpest recoil in 9mm while others say it's quite soft-shooting.