The recently released X: Rebirth sure gives these games a run for their money. Unlike some of the games listed, dev time for X was around 7 years. We can't say that the game was re-arranged in the last hour (like that Superman game). The general consensus is that the publisher said "enough is enough" and forced a release.
X is a bit of a niche series (Hyper-detailed, hyper-complex 4X), but X: Rebirth was supposed to be a much more accessible re-invention. Instead, it is/was an unplayable mess that has been universally reviewed like this: http://www.ign.com/articles/2013/12/02/x-rebirth-review
I'm not sure if it is buggy enough to be considered the buggiest game of all time, but it is definitely in the discussion for that distinction. Fortunately, the developers have spent years after release patching their previous X titles, so maybe some day Rebirth will be playable. In the meantime, stuff like flying around, loading saved games, the entire economy stopping randomly, the inability to complete storyline missions, friendly AI not working, random crashes, and a huge pile of other bugs make this game a mess of massive proportions.
X is a bit of a niche series (Hyper-detailed, hyper-complex 4X), but X: Rebirth was supposed to be a much more accessible re-invention. Instead, it is/was an unplayable mess that has been universally reviewed like this: http://www.ign.com/articles/2013/12/02/x-rebirth-review
I'm not sure if it is buggy enough to be considered the buggiest game of all time, but it is definitely in the discussion for that distinction. Fortunately, the developers have spent years after release patching their previous X titles, so maybe some day Rebirth will be playable. In the meantime, stuff like flying around, loading saved games, the entire economy stopping randomly, the inability to complete storyline missions, friendly AI not working, random crashes, and a huge pile of other bugs make this game a mess of massive proportions.