My opinion in current gen:
Don't like Xbox exclusives and MS in general - they seem aimless with no clear vision. They have to moneyhat constantly rather than innovate and entice devs to their console (just look at the parity clause etc). The games consist of mostly the same games from 10 years ago. More dudebro like Gears, Halo, Forza and now Titanfall. The worst thing about it all is that none of these games were very good in the first place imo. They were just boring.
The UI is just bad on XB1. Slow confusing and messy. Put it this way with a gamerscore of 400k I haven't switched on my XB1 in two months. Never gets used. If it had more appealing games I'd use it but it really doesn't and looks like that won't change either. I'm not excited about Halo 5, Crackdown, Scalebound.
ReCore and Quabtum Break seem interesting but that's two games I'm excited about in what will be 3 years eventually. Don't care much about power differences but that doesn't help with multiplats either,
PS - has a lot of games I play and love. Yakuza, indie games, jrpgs. Uncharted is much more appealing than Tomb Raider for me. I feel Sony try and innovate more with their games such as Last Guardian, Journey, God of War, SotC, Horizon, Last of Us, Puppeteer. None of these types of games exist anywhere else. It's all about the games and I absolutely love the PS3/4/Vita for this reason alone. They have a lot of protagonists which are memorable too like Kratos and characters from ND. Even the more niche titles are fantastic. Like Steins Gate currently playing this and didn't even know games like this existed on Vita until recently, I'm totally engrossed in it.
On the other hand they're not resurrecting their back catalog of great games and need to do more. Crash Bandicoot, Onimusha, Jak, Suikoden, Valkyrrie Profile etc all need new games or reboots.
Also the PSN has some fantastic sales and deals but the service goes down too often and the speeds aren't great. This needs fixing as its letting them down.