I loved that aspect of RDR, it would be really cool if GTA 5 had it, although to be air the towns in RDR werent as big as Los Santos lol. But there were multiple characters you'd run into a bunch of times. I remember Floyd Brogles I think he was part of a Gang Hideout, *SPOILER AHEAD*
Where I thought he blew up on dynamite but then you'd fight him in duels randomly in towns which I thought was funny, he was also spotted in random towns IIRC. Just stuff like that where you're like "hey I remember this guy from somewhere else" was a really nice touch and made the world of RDR feel alive.
Herbert Mooooooon! I'm, I'm Herbert Moon! I've just been robbed! They went thattaway! (Or whatevs). Don't get me wrong, I liked the feature but how I didn't shoot that guy in the middle of his face every fifth-ish time I passed through Armadillo I'll never know. And damn but I passed through Armadillo a lot.