The Samsung Galaxy S8 like its predecessor, the S7, is compatible with Samsung's Gear VR headset. Gear VR is Samsung's proprietary virtual reality headset which you use to consume VR content like VR games, apps, videos and other type of virtual reality experiences. Samsung also announced the new Gear VR, the one that also comes with a controller. I've read on Android Police website that people who pre-order the S8 will get the Gear VR headset for free.
As mentioned already in this pros and cons page of the Galaxy S8, the Galaxy S8 isn't open for Daydream, at least not by default (rooting is needed for that). So although it's quite disappointing not having the option to enjoy both platforms, if you buy the S8, you can still know that you can at least enjoy Samsung's VR experiences, which are actually among the best out there. I would have liked the S8 to support both Gear VR and Daydream, but as for now, there aren't many apps and games for Daydream anyway, so it's not such a huge miss in my opinion. If you don't mind rooting your S8, you can enjoy Daydream as well.
Gear VR on the other hand has lots of games and apps for it. You can find the list of all the games and app on oculus.com. I've been playing Gear VR games a lot and I really love VR. I found myself playing VR games more than I play regular games. There are some really amazing virtual reality games out there for your Galaxy S8, including Eve Gunjack, Minecraft, Smash Hit, Affected the Manor, Cursed Sanctum and many other great titles. You can watch 360-degree videos and educational apps. VR opens a whole new world for creative possibilities for developers to explore and we can see that in the games and apps that are coming out each week.
Samsung's Gear VR is by far the most popular VR platform to date and for a good reason. I first got a taste of VR when I was in Barcelona in the Galaxy S7 launch event. I was in Place Catalunya, the main square in Barcelona and there was a little room there where they demonstrated Gear VR. I was hooked from the very first time I tried it. It was a rollercoaster experience, but oh boy is was so fun experiencing VR for the first time.
If you haven't tried VR yet, make sure you get Gear VR and try it with the Samsung Galaxy S8, it's an amazing experience that I'm sure that once you try it you just won't be able to stop.
The great thing about consuming VR content with the Galaxy S8 is that it has a large and stunning display with high pixel density, so you get to experience virtual reality in a very high-quality. Don't even think of comparing it to Google Cardboard with a low-res display. I've played Cardboard games on my iPhone 5S and it was a disaster. To enjoy VR as it should be, you need a device that can deliver on that promise. This is where the Galaxy S8 and Gear VR comes into play.
The new Gear VR with the controller will make games and experiences even more immersive and fun. There is nothing more exciting than being able to interact with the objects in the three-dimensional scene in VR. It's a very comfortable headset and with the already 600 available apps (and growing), you won't get bored for a moment. By the way, the Gear VR is compatible with the Galaxy S8, S8+, S7, S7 edge, Note5, S6 edge+, S6 and S6 edge. It has a field of view of 101-degrees, it weights 345 grams - have fun!