For target shooting, bo-mar, no doubt.
Long range, any good V-notch, gold dot sight.
Woods rifle, peep sights.
Action, 15 yards, lo-mount novaks, bar-dot, anything open, fast, and with lots of paint.
Self defense, revolver: Fixed, open cut, well regulated, complimented by a crimson trace setup.
Self defense, auto: Nights, accented by paint, open cut, same as action except with tritium.