So, I'm pretty low level and going to places I shouldn't....In the Northeast, Raul's shack, there are tons, TONS of Deathclaw and Deathclaw young over there. Anyway, I wanted a couple of skill books, so hey, why not try? Well, unsurprisingly, the Deathclaws spotted me and gave chase, I have nothing, NOTHING for them lol
 
Anyway, I decide to run into Raul's shack, and in true Fallout fashion, I was totally expecting that the Deathclaws would come inside and kill my ass, and of course, they did. But I kept loading my auto save just see if I could survive it, and on one attempt they did NOT come inside! Anyway, I'm happy, I get my second skill book for the area and go outside....guess who's waiting? Yeah, two Deathclaw adults and four Deathclaw young --wonderful.
 
So I go into vats and throw a grenade, and the game spazzes, and the adults float upwards into the sky, like being abducted by aliens or some shit! I then kill the young ones with my cowboy repeater with armor piercing bullets, and barely, BARELY survive. Then as I'm walking away, the adults fall back down and are half way in the environment, like clipped into it. Then I get 2 experience points each! BIZAARE! So I made a new save quickly and rebooted the game, got my skill books!

I was walking around the Mojave when out of nowhere this long stretchy thing came flying by, looked like a stretched out Powder Ganger that was thrown like a rubber band by the game engine.

I shot one of those pig things once, and it's body flew like 20 feet in the air and like 20 feet back.  Not that neat, but it was funny.

My companion lily's melee weapon "bumper sword" is detached from her body by about two in game feet and facing the wrong way. When she hits people it just looks like she's using telekenisis to manipulate it as it flies all over the place.

Crashing my first few times going to Hoover Dam was a blast.

My favourite so far is my companions teleporting around places.  I love walking up stairs, opening a door, and having Boone just standing there.

I was walking and then suddenly got trapped in the mountains, late texture pop out. 

i haven't had enough time with new vegas to have anything crazy happen but one from Fallout 3 still makes me laugh thinking about it. 
 
i was in The Mall just coming out of one of the subway tunnels there. i was on the quest to help the slaves.  
i was encountering that bug where the slaves didn't show up so i started heading toward the washington monument to kill time and bash in some super mutant skulls.  
suddenly i heard a distant explosion and saw some smoke. figured it was the brotherhood having it out with the mutants and kept on going.  
about 30 seconds later i was completely obliterated by a bus that fell from the sky. i have tried recreating that scenario over and over and have yet to identify where the magic sky bus came from.

In a death sequence my charactors head got stuck on a fence and the body continued to fall creating a bizarre cartoon style streched neck.
 
In another, a specific important NPC was floating high in the air mimicking like he was riding a horse... which i don't even think is an actual animation in the game.

This wasn't particularly spectacular, but I was just walking around and suddenly my ps3 rebooted by itself.

" I was walking around the Mojave when out of nowhere this long stretchy thing came flying by, looked like a stretched out Powder Ganger that was thrown like a rubber band by the game engine. "

" I was walking around the Mojave when out of nowhere this long stretchy thing came flying by, looked like a stretched out Powder Ganger that was thrown like a rubber band by the game engine. "