PS4 + Wii U.
Best combo for the most quality exclusives as well as the multiplats. Best combo for price as well, not to mention the Wii U is free online, so you'll only have to pay for PS4 online. PS4 and Xbone together would be highway robbery per month/year.
3DS is all you need on the handheld front for DS and 3DS games. Vita might become worth it with the PS4 streaming, though. We'll see.
So in short, Nintendo and Sony take this. I have a feeling Microsoft is screwed this generation.
(not counting PC or iPad/iPhones in this)