I've had a couple of wtf moments in my time of playing fallout games.
In fallout new vegas I entered Sloan, this was just after I had cleaned out primm so I wasn't that developed yet.
I sneak around in there trying to find a nice spot for assasinating snuffles, only for fun of course it wasn't anything I was gonna save Iwas just fooling about.
Then it says "danger" and I am like "wtf why?" and it keeps to say caution while I keep sneaking around. then when I'm closer to the road the deathclaw alpha male suddenly storms alongside the road and into Sloan and slays everything in a matter of seconds, all the workers, snuffles, ed-e and that guy that runs the place.
I hid behind the rock at the entry while he slowly went around it looking for me, I got two shots at his face with my sturdy caravan shotgun before I became deathclaw snack.
The first time playing Fallout 3 and entering the first town with the schoolhouse. gets around the corner..
RAIDERASSHOLE: I want his fucking head on a plate!
ME: What the fuck?! Then I killed one and ran for my life.
And the first time I met a super mutant after I crossed the bridge in fallout 3 and he likes jumps down from somewhere and stand pretty much on my face and I'm thinking: "Shit I'm so dead, but i ain't going down without a fight" so I pull out my flame thrower and burns the shit out of that green mother fucker while screming in utter horror in front of my screen.
I
got really surpised when he died so easily and i survived without a scratch. But then i ran as hell beacuse his pals were firing at me from above.
And the first time i met that giant super mutant behemoth in super mutant territory in fallout 3.
One really creepy wtf moment happened in new vegas in vault 3 I think it was, the one in the strip, I went on a murdering streek with my grenade launcher down there and blew everyone to pieces. Then when I walked around looking for more people to kill I see four guys in a room and sends in some grenades killing them all. Then when I enter it's like 15 bodies in there... it turns out it was everyone I killed so far in the vault somehow teleported to that room. Scary...