Unless for special applications, roll, profile or collet crimp for revolver handloads. Taper "crimp", aka "deflaring" die for semi-auto handloads. Many still shoot/reload for S&W Model 52 pistols and need a taper crimp. Plated bullets are recommended to use taper crimp (I will not/do not use plated for any revolver use, semi-auto handloads on rare occasions and only for experimenting or if I have no jacketed or run out of lead alloy).

And just like almost every other method of reloading, there are "exceptions" and personal preferences. I have loaded a lot of 38 Special wadcutters both HBWC and DEWC and lightly roll crimped, but many prefer a taper crimp. Worked quite well for me but I did not compete in Bullseye Shooting and my handloads were more accurate than I could shoot...