I think that pads are pretty nice with blues, because you are working off the actuation point, which is still a bit higher than the pad.
For others, I like O-rings, the softer and thinner the better. I don't want to change the travel any more than I have to, and do want the cushion all the way at the bottom.
If it were possible to put O-rings on buckling springs, I would do it. They would be nice on Alps, too, since the actuation point is so high.