I don't really understand why these bugs even exist, I found most of them within the first hour of playing the game. Usually when a dev releases a new game with an engine they've used previously they improve upon things but in this case they've introduced bugs that didn't even exist in Fallout 3. Below are some annoying bugs I've found so far.
1) When healing yourself with items that heal less than a stimpak your health level doesn't update in the pipboy screen. You have to exit the pipboy screen and go back in to get your true health level, this is critical when you're in the middle of a battle.
2) When you level up you hear the level up sound but the screen to distribute skill points doesn't pop up for two to three minutes later.
3) The screen sometimes jumps and propels you forward when you're barely moving. I found this annoying when in small rooms trying to pick up things.
4) Enemies stuck in terrain where weapons do not effect them. This was a Fallout 3 issue as well but it seems much more prevalent in New Vegas.
Either Bethesda/Obsidian didn't bug test this game well or I'm the exception and am amazing at finding bugs, I strongly doubt the latter.
I have yet to have Number 1 do that to me...
Number 2 has happened i think 2 times and im 17 right now.
3 is annoying when trying to disarm trip wires and mines
Haven't seen number 4 yet but that sounds annoying.
Hopefully more patches come out fast to help fix this stuff, and hopefully it doesnt take forever for DLC. I find myself just wandering around looking for stuff just so i dont finish the game and end up bored out of my mind when the new DLC stuff comes out, and i rather do it on this guy cause hard core mode will be bare hands lol.