Okay, would like to make a biome map:
Savage:Radioactive areas. Wooh .Bigger variants of creatures, like Albino Yuo Gui, would live here, along with there lesser kin. Probably has horrors unseen elswhere in the lower levels. Glowing ones, too, perhapes underground leading there cave ghoul followers. But hey, no raiders! They all evolved into mutents and centaurs by now!
Neutral: Good old wasteland. Everyone gets a slice. Nothing overly powerful, but still has lovley things like Deathclaws and such wondering around. Raider and Wastelander homes alike, along with mutents hillbilly folk. Fun.
Benign: Places with some civilised life, it be cultests or a wastlander town. Ghouls might live here, too. May or may not be safe to walk though in later versions. Most likely has surving machines, but probably has pests. Like giant wasps.
"Good": Ye ol' vaulties homeland. Little to nothing with FEV mutations, but still dangerus. Might have wandering mechines outside, like a MR handy or Eyebots. Most you might have to deal with is the occasinal attack by infected and perhapes someone being bittion by a radcreature. Oh, and the raiders. And all the experamental horrors that they where working on, like Canius Sapians and Hydra spawn, might make a snack out of you if they find out your little town exists.
Evil: Raiders and Mutents and more! Enjoy your nightmares. FEV infused. In later versions of the game, drinking the water might give you tumers. Or kill you.