5 with Journey.
Before you claim Sonygaf and become another griever on twitter:
I don't think other games deserved it more than them. Sure 2012 had Walking Dead, and that year they were really close, like less than 20 points, either deserved it. This year runner ups were W3 and MGSV, both great games with flaws (gameplay former, content latter). BB was the complete package and Gaf took note.
To be completely frank BB simply doesn't do story in a standard manner, it's more akin to a puzzle or fortune-telling, but it works as it engages players in creating their own head-canon, and as "indocrtrination theory" & ME3 ending debacle taught us, sometimes fan-fiction can be better then devs' creations. So BB in a way bypasses this issue.
The perceived lack of flaws of Bloodborne (mind, it's not a game wout some misteps IMO - lack of build variety, chalice dungeons, so-so MP) is more a result of it being a very focused game - it does one thing, but does it extremely well - however "complete package" label is sort of misguiding, because the difference in scope between BB & TW3, makes comparing these two titles is kind of useless.
Ultimately these kinds of plebiscites are about choosing what kind of experience was most compelling to people voting, and undeniably BB excels in the area of its specialisation (and as DS2 example shows, it's not smth given, even in case of Soulsborne games), and is definitely a game that deserves accolades.
PS. And please can with stop with the "objectively better" shtick? All GotY threads are so full of this and in entertainment it make less then little sense - the only thing that is really inter-subjectively (never objectively, as we are not talking about reality, but norms & conventions) evaluable is craft, ie. mostly technical stuff, the rest is subject to personal preference.