I would have to say Rockstar. Out of all developers they are the only one that always kiss Sony's ass even if they're making games for other platforms.
I know why some would say Konami which in my opinion is not the case. It's only Kojima bias towards PS3 cuz he likes to have the latest technology. If the Xbox had had the latest technology it would be otherwise.
Also I think its clear that Square-Enix will jump ships at the sign of money like there's no tomorrow








