feel like this should have it's own post bc the original post got so long, anyways, feeling insane abt the fact that dean owned not one but TWO pretty guns
The iconic pretty gun that Dean uses is the Colt M1911A1, and his model is notably embellished with engravings and ivory sides. I erroneously referred to them as pearl but, well, Dean also owns a gun with a mother-of-pearl grip, the Taurus PT92AFS, which is the gun that eventually becomes Sam's go-to gun. However, we don't see Sam primarily using it until season 2 and beyond. In the first season, it's used three times. It first appears in 1x06 Skin and is first used by Dean to kill the Shifter. They both then use it in 1x10, Dean actually hands this gun to Sam, ** though the one in this episode doesn't have the pearl grips. And then the pearl grip one is again exclusively used by Dean in 1x14.
And since Sam didn't come from Stanford with his own gun in tow, and from the usage of the gun prior to s2, we can infer that the mother-of-pearl gun was also originally Dean's before Sam eventually adopts it.
Another note I want to preserve in its own post, is the fact that John uses a Colt M1911A1 to kill the shtriga in 1x18, but it is notably a plain gun of that model. No engraving and with dark wood sides instead of the ivory sides. Which again speaks to how different Dean's personal tastes are, and how it deviates from the hunter's norms in-world of preferring things simple and plain, and deriding frivolous embellishment, beauty, and adornment. Dean's got specific tastes and they contrast starkly with the hunting world's expectations and cultural norms within spn.
you can check out the references to each gun's usage throughout the show on the SuperWiki's weapon's page.