Special : Virtual Cinemas 
I am a big fan of using these: to watch youtube videos in 2D, and watch movies from DVD/Bluray. It adds to the immersion, and gives you so much bigger a screen.
What is it about? You sit in a three-dimensional, stereoscopically displayed moviehall, and watch the content of your choice in traditional 2D on the big white screen like in a real cinema. That way, you can also copy the whole desktop you usually see on your monitor, can operate it with mouse or VR controllers. And with a virtual keyboard (Window's own onboard keybord). Youtube? No problem. DVD, Bluray? you need a harddriuve, and the usual playing software like before. Streaming content? Shouldnt be an issue at all, like without VR. Its all functioning the same way. Thats why it is called "Virtual Desktop".
Like in real life, you choose not only your wanted film for the evening, but also, if the film is shown in two or three cinemas in your home town, the moviehall of your preference.
These environments come as workshop items for "Virtual Deskptop", which is available in the Steam Shop for I think 12 or 14 coins. I definitely recommend to get this one, its a must have, imo.
All these themes are free except just one, which costed me 1 or 2 euros. Thats the big screen you see in the video above, and that comes in a light and a dark theme where the seats and the moviegall are less reflective and less bright. You want that (darker) screen, due to its monumental size (and then play Wreckfest on it...
). Its the biggest moviescreen available in VR, as far as I know. It mimics the Highmaxx cinema in Sydney harbour which was teared down some years ago, so you sit in a real historic place!
Highmaxx Cinema Dark Theme
A theme I newly discovered and which I really like a very lot, is this one: I is very immerisve, even has some slowly animated audience, it really gives you the looks of a medium-sized modern every-city-moviehall. The screensize suits almost all opportunities equally well. This one convinces me right because it is not more and not less than just a realstic modern cinema.
Cinema (Modern)
This one is of equal quality, but has a very different mood, reminds more of older-fashioned moviehalls as they were common in the 80s. Small details add to the flair: the popcorn buckets, the cola-cups... A small audience is present. The screenshots are a bit dark. I think its the same author like the one before.
Cinema (Classical)
An unspectacular, but well-functioning big screen:
Theatre Large Screen
And the last of the bigger screens is this, I use it not a lot, but it is reasonably sized and okay, may come welcomed if wanting a change while using virtual cinemas a lot.
Cinema Screen
Again, as a reminder: desktops mirrored on the movie screen work and function the same way like the one on your monitor. Except the Highmaxx, all themes are free.