9. Batman: Arkham Origins
This one is a shame, as 2013's Batman: Arkham Origins was a terrific experience that came very close to reaching the heights of the games that proceeded it.
Unfortunately, developers Warner Bros. Montreal made the fatal mistake of not being called Rocksteady. The Arkham-verse was seen by many as Rocksteady's world, and it was clear that the only reason WB Montreal were making Origins was because the publishers didn't want such a large gap between the release of 2011's Arkham City and 2015's Arkham Knight.
To make things worse, long-time fan favourites Kevin Conroy and Mark Hamill were replaced in their roles as Batman and The Joker in favour of younger sounding alternatives.
Furthermore, WB Montreal's choice to focus the game on the Joker, despite his death in Arkham City, left many who were excited to experience a new kind of story in the Arkham-verse disappointed. Despite heavily pushing Black Mask as the lead villain, it was quickly revealed this was actually Joker pulling the strings, leaving many criticising WB Montreal's lack of creativity.
Overall, this meant that despite crafting an excellent game, which in some aspects was better than the Rocksteady games, gamers would never universally accept Origins as being on equal footing with the Rocksteady titles.