I prefer a .125" wide black undercut front sight blade of a height suitable to allow zeroing at dead on to no more than 1" high @ 25 yds. with the rear sight 1 or 2 clicks from the bottom.

For a rear sight, I want a rugged finely adjustable steel sight, preferrably the blade angled very slightly to the rear, and with the top edge of the blade either angled very slightly to the front, or level, so as not to reflect light off the top. I want the notch to be at least .125" wide, and at least as deep as it is wide. For a Ruger, this means a Bowen Target rear sight.Period. For a FA, a PG rear sight, or for a S&W, a stock screw adjustable unit (although they're not as rugged as I like). Elliason only on a Colt.
I prefer a black rear blade but can live with a white outline. I've tried aperture sights on handguns, and brass, white, and fiber optic green and red pipes, but none have given me the precision I want as well as the above set-ups.