If I have to pick one console, I'll go with a Nintendo console. I've grown up with their games so there's a nostalgia and history connected to the company and their franchises that I can't find elsewhere. I also believe that they truly continue to make great games that don't simply capitalize off of that nostalgia. Lately I find myself disagreeing with some of the company's opinions and goals, but bottom line, they still make the games that I love best.
Sony's first-party lineup has really started to win me over in recent years, however. Games like Ape Escape, Jak, Ratchet & Clank, Sly Cooper have absolutely satiated my undying love for platformers. Then there's ICO, which is one of the finest gaming experiences I've had in the past several years. And of course, Sony's also got that 800-pound gorilla named Gran Turismo.