Very interesting question.
To me what I like the most, so not the only thing I like, but what I find most interesting, is the ability to "teleport" my self into "almost" any car and any track in existence past and present.
I have started "SIM" racing before cockpit view, back then you really needed imagination to convince yourself you are actually driving anything anywhere, then a wheel, then cockpit view and finally VR and Tactile in a full fledged rig, is closing the gap.
Some time to a level that can be very convincing.
So, for me, any 2020 SIM with sub par VR, low cockpit details, no driver animation, average graphic, feels backward and does not "teleport" me anywhere.
That is why,
for me, the new GT4 DLC from ACC is so exiting.
Outstanding graphic details and VR, Outstanding and ultra accurate cockpit, best of class driver animation, outstanding laser scanned accurate tracks, will give me the "I am there" feeling that I particularly enjoy, in 2020, when sitting in my rig and wearing my goggles.
Good bye "real" world and welcome to the Holodeck. Beam me up Scotty, their is no sign of intelligent life around here!