I like somewhere between 80-85, say 82.5 ish, but unfortunately, there is major warping. But the default is like binoculars and I could never stand it. Over time, the warping (fisheye?) started to really annoy me, so I'd lower it by 1 point... then another. Over time it ended up about 73, then 72. Eventually, I ended up at 70. So I've been using 70 for a long time now. I just can't stand the warping of any higher, nor the binoculars of any lower.
It seems to me that the human field of vision is around 3 times wider than widescreen, if I were to take a guess. Default svcks. Maybe I should set up 3 monitors.

The eyes focus on a very small point, the rest of the view would be out of focus. Anyway this requires head tracking to replicate on monitors. Head tracking for moving the camera view around. Again, anything to the sides should be out of focus.
From some research I've done, it seems that your brain "makes up" much of what is out of focus, or something. I didn't retain enough to elaborate.