Supposedly the 27.5 million figure is coming straight from Rockstar. This is a 2011 figure, so I wouldn't confirm or deny that the game sold more than 30 million copies across all versions, combining digital and retail. At any rate, Mario Kart was bundled. GTA had multiple versions and re-releases. We should invalidate these sales, no? ;)
I personally think it is worth noting that the best-selling non-bundled (not bundled with either a console or peripheral) single-version game ever is... rather impossible to find. I found one seemingly official bundle for Wii + Super Mario Galaxy, and that's the closest I'm probably going to get.
3DS Friend Code: 0645 - 5827 - 5788
WayForward Kickstarter is best kickstarter: http://www.kickstarter.com/projects/1236620800/shantae-half-genie-hero
