I just got a PS4 in mid-December and immediately delved into two of the free games that came with my bundle: Far Cry 4 (50% complete) and LittleBigPlanet 3 (completed story campaign and Pop-up Academy). I also played the free Plus game Contrast and bought and completed The Walking Dead season 2. I'm now wrapping up my third 100% completion of Flower, which looks a plays amazing on the PS4 (I previously played it on PS3 and Vita).
Not to neglect my PS3 backlog completely, I've also put some time into Madden 15, Borderlands 2 DLC, Dishonored DLC, and this week I started the one LEGO game to rule them all Lord of the Rings.
Next up are Skyrim Legendary Edition, which I purchased the week before I decided to jump on a PS4 bundle, and some obscure little game that came with my PS4 bundle, The Last of Us Remastered. I know it may seem odd to start LEGO LOTR ahead of Skyrim and TLOUR, but I'm afraid the longer I wait on these backlog titles, the less chance there is that I will ever get around to playing them. By contrast, there's no way I'm NOT playing Skyrim and TLOUR, even if it doesn't happen for another six months.
Looking at the above, I seem to have completely abandoned my Vita, which I haven't fired up since the Thanksgiving holiday weekend to play Escape Plan.