Well, I'll start with what I think has the worst, and unsurprisingly it's GTA 5. I created this thread bc I just finished the game again (barely, it's so bad it was forced) and it got me thinking. Now the ending I always choose is "Death Wish" simply bc it's the canon ending, but it is beyond stupid how it ends.
Even the very first time I played the game and still had that shock and awe feeling I knew it was bad. For one thing, I think the story should have been written in a way that would have allowed us to kill off ANY of the 3 protags, not just Michael or Trevor. The whole shootout at the Foundry between our protags, Merryweather, and the FIB just felt like Rockstar wanted to throw in 1 big final shootout for the heck of it. But the worst part, was after that when each protag killed the enemy of the other protag: Frank killed Wei Cheng for Trevor, Michael killed Stretch for Frank, and Trevor killed Haines for Michael, and then all 3 of them killed Weston. I know right. The first time I played the game I didn't know who was who at the end. lol. Here's the kicker though, Stretch was standing on a basketball court with a group of Ballas just out in the open. Why? He must've known that Franklin or Lamar would not be happy having known that he was behind that ambush out in the sticks and might try to kill him, so why wasn't he laying low in a crack house somewhere or whatever. Instead he is just standing there for easy pickings and it doesn't make sense. And, after Trevor attacks Merryweather and their assets the entire game, they apparently just say "Devin Weston's dead huh...then oh well" and forget all about Trevor and the gold from the previous heist...which is the reason for the shootout at the Foundry in the first place. See how things don't really add up. All in all though, I just do not like how all the antagonists in the whole game are killed one after the other as if it were that easy. It's like the writers grew tired and just slapped an ending on an already mediocre game.
Added a "poll" on the suggestion of a fellow poster to make things easier.
Update: I decided to go ahead and add spin off games as well as 2D games to the poll. I did not realize so many of you actually played them. My apologies for the misconception. Change your answer if you want.