Microsoft
Pros: Microsoft has the best online in general (multiplayer and xbox live experience) and they have a good eye for acquiring new franchises from other companies.
Cons: They need to learn how to make competitive new IPs (the bread and butter of what it means to exist in the console realm)
Sony
Pros: The only company that takes risk all gen long in creating or themselves in the development of new IP's. They aren't afraid to hang up old characters and make new ones. They have the strongest in-house storybased gaming experience of all of the brands. The platinum trophies are a great cap to the achievement system. It makes me want to be a completionist.
Cons: Their online sucks compared to Microsoft and so does their marketing.
Nintendo
Pros: Arguably the best exclusives in the biz and the most affordable hardware to buy it on as well.
Cons: Not very open minded, which makes them bad with third party. They need to up their hardware game so third parties wont exclude them next gen.