Played Fallout New Vegas' Old World Blues Expansion again recently, and while it is filled with lolcows and horrorcows, Dr. Borous of the Think Tank stands head and shoulders above them all.
For starters, he's that nerdy kid who got picked on by school bullies who grew up to become a mad scientist who never grew up past his shitty high school experience and despite his intellect, is still a massive whining manbaby about it.
When you go through his school themed dungeon, it goes from pathetic to horrifying when you realize his idea of revenge would involve siccing the cyberdogs and nightstalkers you have to fight on that bully he always hated. Worse, you find out he's a control freak with a really severe god complex as well.
The horror continues when you realize not only is he responsible for the rattlesnake/coyote nightstalker hybrids that now infest the Mojave, he also made the Cazadores, and his head is so far up his own ass he truly believes they are perfect and their creation didn't backfire in any way (despite having access to his own research facilities, he's completely blind to the fact they've reproduced despite them supposedly being designed to be sterile).
He does have one humanizing trait though: when he was still human and not a brain in a tank; he truly loved his dog Gabe, but even this becomes horrifying when you realize, courtesy of his own account, he was treating the only being in the world that loved him unconditionally like a science experiment, and even though you can pass some speech checks to make Borous realize how much he hurt the one being who loved him unconditionally, his sociopathy is so advanced he tries to bury that knowledge since it makes him uncomfortable. Also, while difficult to do, if Gabe manages to survive the encounter with you and the roboscorpions that try to kill you, Borous is glad you spared Gabe's life, but is still so deranged he doesn't realize his beloved pet is still a monster created by his own hands.
Of course, most of his colleagues aren't much better, but frankly, none of them come close to his level of madness. Klein is a pretentious dumbass who tries to come off as smarter than he is, but is both the sanest and thus most dangerous member of the Think Tank. Dala is so obsessed with biology she sees experimenting on humans as "playing with teddy bears" (as a human she liked actual teddy bears, which merged with her mad scientist personality), though it's this that also allows her retain most of her own humanity ironically enough. Zero is basically Rusty Venture from the Venture Brothers, and while a bitter douche, remains quite human with a little self esteem boost, and it's hard to tell how screwed up 8 is or not.