People surviving a massive ammount of damage, in general, was always something I disliked but simply had to forgive, with the whole Fallout series.
(One of the reasons I liked the combat of FoT, since there a sudden blast of a shotgun will typically bring a person right down)
During a single battle you can shoot a guy in one eye, then the other eye, then the balls, then the first eye again, and he keeps fighting - even keeps taunting you, damn - know when you're beaten man! *shoots the first eye for the third time*
NV also has a few eternal annoyances, that just have to be... such as my companions fleeing away from me, whenever we have arrived at our destination. Role-play wise it obviously makes so... much... sense... "BRB! :O" "not this again -.-"
That's it! I should just pretend they have to go potty!