Not sure if I should get a ps4 with tax return. Hmmmmm.
Depends: Games before Summer.
Do you like Digital Pinball? PS4 version of Pinball Arcade has a new lighting model which looks gorgeous (needs a sound patch though as it's using iOS sound on accident and will be patched with first patch); I've spent a good chunk of my time on PS4 with S1 of this.
ACIV, best version if you don't have a crazy powerful PC and a good open world sailing game w/flaws. Nice story about the golden age of Pirates and the first likeable lead since Ezio.
Resogun, pretty sweet. Like it better than Super Stardust.
MGSV Ground Zeroes - MGSV Ground Zeroes, but best looking/running version. Same will be true for MGSV Phantom Pain most likely next year.
Infamous SS - Do you like Infamous? More Infamous but better looking and hopefully even better playing, but shorter.
Yakuza Isshin - Dunno if this will come over, but if you're willing to import this will be the cleanest looking and best running version.
Dynasty Warriors 8XL - Will be the best version of this.
The Witness/some other indie stuff - Most of these are on steam so I normally wouldn't care since I'd grab them on PC, but with PS+ I keep getting free ones so that's cool. Already Don't Starve & Outlast were free, guessing Octodad might be soon.
Driveclub - Makers of Motorstorm with some PGR and Wipeout staff, PGR/NFS-styled real car arcade racing. Looks nice but with all these delays who knows how it'll turn out.