I'm not so sure about MGSV...after the initial rush, a lot of negative (user) feedback claim it suffers from weak and "stretched", thin story, very repetitive missions, and poor world design. Plus, lot of people claim the game doesn't even feel finished in it's current state, story wise at least.
I think Fallout IV and Wild Hunt will fight it out in the end. In the end, past the hype, it will boil down to how much effort Bethesda has made to improve writing on their end. It could be their best game so far...or the most comical we've seen. Engine is a bit of a setback for Beth, but their games were never graphical powerhouses so far either. I'm more worried they'll push the limitations past what the good ol' Gamebryo can handle to keep up with competition.