+ 1 for the Makarov. Especially the older models, since its made in the same factory as the real gun all the parts used are very high quality and it actually uses many real parts.

The witness has one of the worst build qualities imo. Cheap pistol but many of the internals are made out of plastic and after about 2000 shots you will notice things getting loose and the gun failing to perform as it once did. Also the metal used is a very cheap alloy that has not been mixed properly (visible if you strip the paint).

I found the crossman c41 to have pretty good build quality. Also the magnum research desert eagle has a pretty good internal build although the external plastic body feels kinda flimsy.