6. Halo 4 - A New Protagonist
At the end of Halo 3, series protagonist Master Chief enters cryonic sleep and is left drifting through the endless void of space, seemingly forever.
Whilst a little bit on the gloomy side, this could have been a fitting and poignant ending for the central character of an epic universe-spanning trilogy. The next two instalments, Halo 3: ODST and Halo: Reach, focused on original characters and explored different events in Halo's timeline - a welcome change.
However, Microsoft felt that their faceless, personality-devoid tin soldier needed a comeback and formed 343 Industries, a division dedicated solely to wringing as much cash out of the franchise as possible in the form of unnecessary sequels and endless remasters.
Thus, Halo 4 was born, Microsoft made loads of money and the franchise didn't budge one solitary inch.
While the game itself was enjoyable enough, the reintroduction of Master Chief was a step back for the franchise.
A new protagonist would have breathed some new life into the series, and would have had more character than the Chief (which is any at all), but 343 Industries ploughed on with Master Chief's story, resulting in a franchise which feels like it's refusing to move on or innovate where its narrative is concerned.