Alright, let's see.
You got your Parchute Pants Wearing Paramilitary Guys, who like to think that they're good guys, bringing Order to the Chaos of the Wastelands and stuff, but we all know they go a little overboard with that acceptable losses junk, especially if the stress is getting to 'em all, and Dennis Hopper is their General, and he's an ether-huffing masochist who's teetering on the brink of a nervous breakdown or something, as usual.
Still, they probably got tons of ammo and cool GI JOE vehicles like tanks and shit.
Then you got your Radioactive Bloodthirsty Bomb-worshipping Wendigo Cannibal Folk, who have gone over to the Dark Side and think Mutations are a sign that you've been Touched by the Gods of Chaos.
Y'know, Hill's-Have-Eyes slash Leatherface-style.
And sometimes its hard to tell the difference between those mutant cannibal guys and Lord Humungus's Purple Mohawk Dudes with the pink bird feathers and the He-man Wrestling Outfits and the Regular Half-Insane Toothless Hillbilly Villagers Who Run Repair Shops and Gas Stations But Don't Eat People.
Then you got the Silver Spacesuit Utopians, with all their advanced technology and hot chicks from the 80s, in a Boy and His Dog they were the Original Vault Dwellers who went sterile and needed to kidnap dudes to impregnate all their women, they're a mix of scientists and corporate shmucks, I guess.
And then there's the People that have been stuck down in Bomb Shelters since the fifties, y'know, the Aw Shucks Leave It To Beaver People, who can't help but be Good Guys since they don't know any better.
Oh, and then you have your Standard Road-Nomad Muscle Car Post-Apocalyptic Survivalist Loner Cowboy Hero With Dog dudes, in the Cool Leather Outfits, and dudes like the Gyrocaptain, who are supposed to be what happens to Regular People Like Us, I guess, 'cause they don't have any obvious philosophical flaws designed to prove some author's cheesy-ass point about the human condition, aside from the Standard Survival-Vs-Morality thing.
There's always room for plenty more weird little gangs of people, but those are all the Archtype Ones.
In Fallout, the Paramilitary Guys were kinda mixed with the Scientific Utopians (and the Utopians were mixed with the Bomb Shelter Guys from the Fifties), they had kickass technology and Exo-skeleton Armor (that was originally Steam Punk Looking but ended up being all Silver Spacesuit in the end) and stuff that you could steal, which is cool and everything, I guess, even though its pretty fake, y'know.
But if there was ever a good reason to be fake about something, it'd be kickass Exo-Skeleton Armor, right?
I don't think Zombies count as a kind of people, 'cause they're monsters, really, y'know, just like swarms of Flesh Dissolving Mutant Cockroaches (gotta have those).
And if you make some Zombies smart enough to be a kind of people, insteada just target practice, then yer getting into a weird area where you gotta deal with Undead Culture, y'know, like Undead Guys talking about Undead Stuff to each other and Ghosts and all that supernatural junk, and they'd lose some of the sense of Silent Evil Mystery they got and they'd prolly turn kinda campy (like the Ghouls from Fallout), although the Vampire Zombies guys from the Last Man On Earth weren't too bad, 'cause they had that creepy Join Us-Body Snatcher effect going for 'em.
I'd throw in some Flying Saucer sitings and shit every once in a while just to maintain an aura of unpredictability, y'know, especially in a Post-Nuclear thing with Bomb Shelter Guys From the Fifties, what with the way UFOs were always supposed to be buzzing around Top Secret Nuclear Testing Places and stuff.
Plus Crazy Hillbilly Gas Station Guys that Worship Aliens are even scarier than the ones that don't.
So that's a pretty good mix of stuff, I think.
Sure beats the shit outta elves and gnomes (although there ain't no reason you can't have kickass shorties like that Water Selling Dude from the Six String Samurai and the Master of Master Blaster).