Until recently, my answer to this question would have been Saints Row 2. I played the PC port of the game on Steam, and it contained its share of problematic glitches. In fact, more than once I found the game to be completely unplayable. Worst was when the screen would randomly blackout in the middle of a mission with the sound still playing in the background. It only happened a handful of times, but even one occurrence of such a glitch is one too many.
But as glitch-ridden as Saints Row 2 was, it doesn’t hold a candle to Fallout: New Vegas.
With the arrival of Fallout 4 in late 2015, I figured it was high time I get myself a piece of all that post-apocalyptic action that had been capturing everyone’s attention. And things started out well enough. I created my character, experienced the horror of nuclear annihilation (fun!), and started my new life on the other side, in wasteland called the “The Commonwealth.” Unfortunately, my relationship with the game petered off for no discernible reason. I became interested in other games, and that was that. I made a couple half-witted attempts at getting back into Fallout 4 at various points over the course of 2016, but they hardly resulted in any significant progression.