I had one crash and 1 mission I couldn't finish. And companions disappeared quite often. I feel like there was more...
Oh yeah: on numerous occasions, I was attacked for no reason. I don't mean by Fiends, the random encounters in Freeside, or conflict due to faction armor/disposition. Sometimes, I would talk to people and finish the conversation (and usually it was mundane dialogue, not a result of me threatening them or the like), then they would decide that New Vegas would be a better place without me.
Aaand (I edit my post, then remember something else over and over): enemies/me falling through the ground. That one is annoying
I might have used the radio for half an hour total during my playthrough. I prefer the more atmospheric music. If I want something 50's-ish, my iPod is chock full of it and with a better selection than the game offers.