WesleyB: I can name a crapload of annual sports games, but that's too predictable.
So my pick for the blandest of all the blandest is..
Martian Gothic: Unification The game starts as a nice Resident Evil-like sci-fi horror game, but later on you discover that the voice acting is so dry it puts you to sleep. That, and you're forced to constantly manage character's items, which murders the pace completely and is a hellish chore.
You see, it's kinda like Maniac Mansion - three characters (who are separated and made to stay separated, because if they do meet each other, they get "unificated" and it's an instant game over), each with their own inventory and sections of the base that requires items to progress that they can access only if other character finds them and sends them via the vac tubes.
Now imagine going back-and-forth, back-and-forth, constantly managing items and making sure you remember you put what item where (because of course you run out of space very often), and then heading straight into the third act in which it's obvious the developers themselves got bored of what they made. Nothing spells bland like trekking through boring caverns of nothing.