I will back Sony. Sony consoles were born out of a fallout between Nintendo and Sony. Not only does Sony handle it's PR better than the other two (most of the time), they also provide a vast diversity in their provided products. Consoles, phones, televisions, tape decks, audio and visual technology, etc. Sony is truly a monster when it comes down to business.
Microsoft may have the cash behind it to push forth with great titles, but the relationship it has with consumers has a shaky track record at best. If you were alive in the 80's, you'd remember mass lawsuits Microsoft was facing, and again in the 90's. The news about poor service on Microsoft's behalf has faded out of the news circuit, mainly because people caught on to the idea that Microsoft was evil, blah blah blah, change the channel.
Nintendo is also running to catch the coattails of the other two as they step into the PC-like realm.
Sony provides the most support to individual developers. Microsoft is just beginning to get the idea. Nintendon't (sorry, but had to say it).
Nintendo is also the strangest of the bunch. They lock up great titles like Metroid for years at a time, and when fans clamor for another side-scrolling shoot 'em up, they put Other M on the shelves. Yeah, great. Instead of playing that game, let's go into the kitchen and play five finger fillet instead? On top of poor licensing, Nintendo also changes the styles of its consoles radically. From a VCR like set up (Famicome was top loaded), to the top load of the SNES and 64, then to the Gamecube and it just got weirder from there.
Microsoft. Kinect. Microsoft supports the Kinect. Microsoft still supports the kinect and puts out games for the kinect on a regular basis despite outcries from the gaming community as a whole. Initial release of the Xbox One made it a mandatory purchase.
Ages ago, Sony backs the Playstation eye. Had better motion capture than the first Kinect. Sony put out games for the Playstation Eye. It did not catch on, Sony dropped games it had planed for the eye. Instead, the eye is now a camera
Sony backs the Playstation move. Develops games for the move. People do not respond well to the move, Sony eventually phases out the move. Meanwhile, great games are being released for the Microsoft Kinect (sarcasm).
Nintendo doesn't release SNES games on the 3DS store, regardless of the abilities of the machine. Poor choice.
Sony puts PS1 games on its store on a regular basis. Currently, due to a fortunate over look, all PS3 slims can play PS1 games. Hacked PS3s can play Xbox 360 discs.
I have no deep knowledge of Microsoft's store. However, it has not had itself hacked if I can remember correctly. However, Microsoft decided not to install a Bluray reader into its consoles, forcing consumers to change out discs, technology I thought to be obsolete. The idea that you pay the same amount for a DVD as Bluray disc is ludicrous.
Sony isn't region-locked. At all. Online gameplay is free.
Microsoft's online support is not free, and thousands of initial machines fail right out of the box (Xbox and again with the Xbox 360). Further investigation proved that thousands more Xbox 360s have major design flaws, causing the units to eat discs, and burn out.
Sony and Nintendo have had relatively fault free releases.
Online support for Nintendo is still a pain. There no doubt there is more reasons out there, but I must retire now.