I currently own a Wii U, XBox One, PS4 and a PS Vita.
Bought all of them, as during the previous generation of consoles (PS3, XBox 360 etc) I didn't own any of them and I felt I'd missed out on a bunch of console exclusives that were pretty damn great.
So far I'm regretting the purchase of the XBox as I've literally got one game I play on it (Halo: MCC), pretty much every other game I bought for it have been shite (Ryse, Forza, Sunset Overdrive).
Wii U has been great, Nintendo titles are always exceedingly well polished and I've bought every major Nintendo title released so far and have had great time playing them with my son (Mario Kart 8 and Smash Bros especially).
PS4 has been the clear winner for me this generation. The console is undeniably more powerful than the Xbox (games always seem to run one notch higher in terms of resolution etc) and the interface just feels better. Big favorite of mine on PS4 has been Destiny, sunk untold hours into that game before I tried ALUK. I'm also a self confessed XIM4 user, which means I can use a keyboard and mouse to play games on the PS4 (or XBox One) and playing Destiny that way has been great, best experience on a console in years.
I don't have any games for my PS Vita, I bought it only for the PS4 remote play functionality, which has been surprisingly good. I live in Somerset and frequently travel to London on business or to see friends and with the Vita in my pocket I can still play full fat console games while away from home. Playing GTA 5 on a handheld is something to marvel at IMO.