My PS4 experience has been nothing short of amazing. I'm playing Destiny and BF: Hardline right now and I'm honestly pleased to know these games are coming out soon. That being said, everything else is also phenomenal. I have so many games it's crazy. I recently picked up Injustice for PS4 which has kept me busy also. If I had to say WHY you would choose a PS4 over an Xbox it would easily be for the value. Same price, better hardware, more support and in my opinion, a nicer lineup. PlanetSide 2 is going to be a humungous release, H1Z1 for the DayZ fans, MK will most likely get exclusive content (Kratos on PS3 plus it debuted at the Sony conference). PlayStation plus will give you great games on PS4 for free (Trine 2 was one of the recent releases).
This might not matter, but Sony is also the only gaming console company known to be exploring Virtual Reality (Project Morpheus). Who knows what this could mean for PlayStation gamers... At the end of the day though, the Xbox is not a bad console. I used to play with one almost daily. You definitely won't feel like you wasted your money if you get one so long as you enjoy the games exclusive to it. If third party multi-plats are what you're interested in, I'd go PS4 100% of the time. I would definitely do some research for your own benefit before deciding.