If you're OK with keyboard mouse/control then this combination will do the job best in terms of best motion (not free though and needs some initial setup to work best:
1) Desktop clone (NOT virtual desktop, big screen because Hz is locked to your desktop screen that is most likely <90 Hz) I recommend vorpx because it can stream directly to your HMD otherwise you may need to configure your headset as a standalone screen in Windows to support 90Hz)
2) mpc hc, (free) hands down best player on windows and the most plugin friendly one.
3) madvr plugin for mpc (free). Chroma doubling/quadrupling depending on ur GPU power.
Need to read through the wiki guide though and do some testing can't configure it out of the box.
It has a smooth motion option as well that works actually nicely BUT if you wanna go further:
4) reclock rounds the fps of your video to a partial of your desired refresh rate maintaining pitch and sync.
5) svp player multiples the rounded fps to desired refresh rate.
I recommend to buy svp as it includes all prog, plugins and pre-configured settings out of the box.
Still need to pimp madvr settings to get most of your GPU. It may take some time until you get the knack of it but it's not that hard.
If you are not into improving the picture quality and
only into geting an insanely better/smoother motion, SVP (SmoothVideoProject) comes with a stand alone drag and drop player additionaly to the mpc/reclock setup player as well.
it is worth mentioning that SVP works with Whirligig! which is a nice affordable player with awesome picture quality. It's a bit heavy to get how whirligig works but after taking a 5 min YouTube course provided by the dev everything should be clear. So if it is more about a fluid picture taking advantage of 90 Hz than about ease of use this is a nice combination as well. It has configurable bindings for Controllers and Keyboard/mouse