In business, those terms are a bit worthless, to be honest. Corporations aren't fixated on 'generations', they're looking at the entire picture.
If we had to break it down like that, though, then I think they all did well, which is amazing.
Microsoft jumped their level of market share by a huge margin. They have to be extremely pleased with that. They took some blows to brand image, yes, but they pretty much shrugged that off. They left the gen in much better shape than they started.
Sony has to be happy with how well they recovered. The early gen was a nightmare. The PS3 started off slowly, the Wii went viral, and Microsoft had a year's head-start. Let's be clear, Microsoft's money (and Halo) made it a foregone conclusion that the PS3 would not have the PS2's market share. Sony did not "lose" that to Microsoft; Microsoft took it. Sony left the generation with all the momentum, though, which I think has translated well for the brand.
The Wii made lots and lots of money. It didn't finish well and I think that hurt the Wii U, but judged only by its upside, the Wii was a monster.
