Albicant on 18 May 2013
Mario and Pokemon are both bigger than Halo or Gran Turismo in my eyes, so I don't think either could claim to be the biggest 1st party title.
Out of the two, I'd put Gran Turismo ahead, though Halo has definitely grown this generation. Halo isn't really massive in Europe, I get the idea that it's bigger in the States tough.
