We've all found something in these games our umpteenth time playing through these games. I just had my first in awhile going back to the Kings in NV after taking care of Benny first. While dealing with Orris' shadiness, I had never noticed the barter option for taking his money off him. If I hadn't already robbed the White Glove Society's cashiers blind & nabbed the gold from the Sierra Madre it would probably feel more rewarding but I still belly laughed at being able to tell that shuckster off grifter Sherlock Holmes style.

Not sure if this qualifies, I didn't realize this until after hundreds of hours of playtime in New Vegas. If you have Boone with you, you can get access to the NCR monorail early without needing the required reputation.

While NV is a much deeper gameplay experience that Falout 3 or 4, there is a lot of just little things that bethesda threw in when making Fallout 3 that just aren't there in NV due to the shortened dev time. My favourite one was a few years ago a friend told me of a note in the Germantown Police Station cells where some mad man wrote flying bananas can't talk over and over again. I'd walked by this so many times, so many years and playthroughs and I never noticed it.

Recently, doing a TTW playthrough I've found a molerat meat packing plant run by some crazy named NPC underground somewhere. Another one I found was a ghoul wearing a party hat that's been killing, and assumingly eating ghoul meat to stay alive. Weird stuff, all found on this recent playtrhough. Coming up for NV's 10th anniversary and this game combined with FO3 is still got things to see and stuff to find, even for people who have been playing it so much in those ten years