For the uninitiated 3DoF means the headset only tracks the rotation of your head, not your heads absolute position as you move around, while 6DoF tracking does both. 6DoF is also much harder to implement.
I want super high res so the quality is comparable to a TV or projector setup, and I want OLED because of contrast performance for dark scenes.
I've had pretty good experience with https://goovis.net/products/g3max specifically for movie watching. It has 2560x1440 (per eye) OLED, so not quite 4K; I do hope to see a proper 4K headset like that some day for a reasonable price.
https://www.amazon.com/Glasses-Massive-Micro-OLED-Augmented-...
For $200 they are good. They are native 1080p Sony micro-OLED panels. Brightness and contrast are excellent. I got them mainly to use when traveling, but I also use them laying in bed sometimes.
The resolution is higher than it seems because the 1080p is only displayed across about a 40 degree horizontal FOV, so the PPD is actually very high at about 49, which is markedly higher than even something like the Apple Vision Pro. It's also RGB stripe OLED. I cannot see the pixels like I can with VR headsets.
But alas, there are issues that bother me like ghosting and other internal reflections inside the lenses. Though all VR headsets I have tried have these issues which bother me, so I am not sure if that will ever actually be solved to a level that is unnoticeable by me.
The other thing about the glasses is that they don't recreate a theater, and a virtual room, so the apparent size of the virtual screen isn't consistent as it mainly depends on your imagination for how big you imagine it being. If you view a virtual screen in a fully virtual environment like Bigscreen Beta, then you can fully trick your brain into making the virtual screen seem as big as you want, even IMAX sized, and it really does feel like it.
The problem with full VR environment headsets and large FOV over 100 degrees means that the virtual screen only takes up at most about half of the panel, because a 55 FOV for a virtual screen on a headset with a 110 FOV is about as big as most people would be comfortable. So then a true 4K per eye headset would still only give you a 1080p victual screen. Though I think this is still a level which is good enough.