I took the plunge last Friday and got a PS4. I got the game Knack. The game is nowhere near as terrible as I have heard. The last hour or so of the game was a bit of a chore, but the title is fun for the most part. You do not get a lot of moves to use, but the situations you run into while playing are challenging enough that boredom never really sets in.
I love the interface. Now I can actually get into the PS store without waiting a whole minute for it to load. I am looking into getting Killzone, Infamous, or Thief next. I am already a Plus member, so I have gotten all the free games for PS4 from the PSN website. I honestly do not know why some are bashing the PS4 library. It is pretty good for only being out 6 months or so.