Pretty much all of my game-breaking glitches are restricted to New Vegas. I love this game to death and I still haven't discovered everything in the vanilla game (to say nothing of the mod-added quests, some of which have literally as much content as one of the DLC; Project Brazil has only released the first chapter and it already takes several hours to complete before dropping you in the bare bones of a sandbox the size of the Capital Wasteland that they plan on turning into a complete package over two more chapters). But damn if it doesn't crash like hell.
The worst part is that it has a nasty tendency to corrupt saves or suffer a sudden game-breaking error that you can't identify, which results in the game lasting for mere seconds before crashing to the desktop and no way to identify or fix the problem beyond hoping that you have an earlier save to reload. Just getting a long-term character who tries to complete several major quest lines can be a chore.