No, BioShock is not the best selling game to come from the 2K stable.
That honour falls to Borderlands 2, which as revealed by Take-Two in its financials last night has now sold over 8.5m copies meaning it has surpassed every title in the BioShock series and also beaten the NBA 2K games.
As of October 30th Borderlands 2 had seen 7.5m copies shipped to retail, with Take-Two at the time saying it was on track to become its best selling title ever.
It will also be ported to PlayStation Vita this year, although it turns out the March 2014 release date announced last month was actually an error.

http://www.mcvuk.com/news/read/borde...g-game/0127628