It depends a lot on the type of game I think. For me and from what I've observed, the motion sickness tends to come from a mismatch between what you're eyes are seeing what what your body is experiencing.
So any game where you're not moving besides when you're actually walking around in meatspace generally doesn't seem to trigger that "oh god you ate the bad mushrooms abort abort" reflex.
The other area this can kind of sneak up on you is if you're trying to use a device/PC that isn't really up to par and the frame rate is dropping. You cross a threshold where it's not quite keeping up with your movements and get the same mismatch between your movement and what your eyes are seeing and it makes you sick.
So to that end, stuff like SUPERHOT VR or Beat Saber you can generally play comfortably for hours. I've thrown my 85 year old grandmother who gets horribly car sick into Job Simulator for an hour without any problems.
It's a pretty short easy leap to any games that provide "blink" movement where you just kinda point at a new spot and suddenly you're there. Literally "blink" and when you open your eyes you're in a different place. A lot of great games support this style of movement and it's usually pretty comfortable--there's no actual motion to the movement. Something like Half Life Alyx has been pretty comfortable and fun (besides being absolutely terrifying waiting for headcrabs or zombies to get me) with this movement method.
Any racing or flight simulators where there's constant motion are generally the stuff that even still get me. I've acclimatized a bit and can actually play them now for an hour or two at a time, but certainly not indefinitely.
EDIT: This is all with an old HTC Vive. I did used to own a Oculus DK2. The extra 15Hz or so refresh rate and a more powerful PC made a _huge_ difference in how sick the simple stuff made me.