I'd try a few things:
I'd hook up my PS4 followed by my PS4 Pro so I can fully appreciate the performance increases (I bet Horizon would look beautiful! And Mass Effect Andromeda soon too!).
I'd try my XBOne for Halo/Forza.
I've got a MSI GL62 gaming laptop and I'd be keen to see how Civilization V/VI look and play on a huge screen :-)
(Waiting to see how Ryzen/Vega play out before I commit to a new full gaming rig, though the 1080Ti's do look awfully nice!)
I've been watching a lot of Breath of the Wild streams on Twitch recently (such a beautiful game!), which have almost convinced me to get a Switch, so if I do I'd try that also.
Hooking up my HTPC (HP N54L) is a given! I'd be able to finally experience having an actual home cinema.
Also, (if I can find it), I'll try digging out my Pi for some RetroPie goodness :-D