Simple, Name a video game that was a let down or parts of it that were.
Mine would have to be Deus Ex.
You mean I can't stay with UNATCO!?
Also one in FNV was that you have to buy a DLC to get sights on the laser pistol (Rifle?), Why should I have to pay for something that should've been there in the beginning? It made me avoid Energy all together.
Fallout 3, Not enough guns or customization options. You do more damage Unarmed. Food isn't worth it's weight IMO. I also wanted to be in the Enclave, BoS in that region was stupid.
These are off the top of my mind.