I totally second this.  A couple facts about my own routine:

• I've been using a Quest 2 for regular (2x-3x weekly) brief exercise sessions for about a year.  In combination with occasional (0.5x-1x weekly) traditional strength training routine and some jogging around the park, this is the most fun I've ever had exercising and the most consistent that I've ever been about it, although I still wish I was doing more.
• I use this basic pair of weighted gloves when I play VR, which makes games like Beat Saber much more of a workout!  I was initially put off by people talking about how it might be bad to use wrist weights because they could cause injury, but I think this is referring to much weights much heavier than 1lb per hand.  In my experience, I haven't come close to anything that feels dangerous -- if you wouldn't fear for your wrists while dancing and holding a pair of largeish apples, you shouldn't have anything to worry about from using relatively light weighted gloves.  I also got some of this foam-exercise-mat stuff to create a defined space in my garage for exercise and VR, which has been nice.
• I use VR games not just as a workout in themselves, but also as a reward to get me to do more ordinary types of exercise.  ie, I'll promise myself "okay -- get through this 1-hour r/bodyweightfitness routine, and then you can chill with an interesting non-exercise VR game for a while to cool off, and then play some fun Beat Saber to cap it all off.
• VR exercise really is extremely convenient.  I live directly across from a park with a nice set of tennis courts, but: Sometimes other people are using the tennis courts!  Sometimes it's dark outside!   Sometimes it's too hot or cold!  Sometimes I don't have anyone who wants to play tennis with me!  Sometimes I just don't feel like going out and doing a bunch of exercise in public!  In all those cases, it's awesome to be able to just do a jam session of Beat Saber in my garage.

And about what games I enjoy:

• I totally second Beat Saber, it's by far my favorite.  I'd also recommend the hilarious and engaging Gorn and the boxing game Creed: Rise to Glory for variety.  Echo Arena, a multiplayer "Ender's Game" style zero-gravity ultimate-frisbee game, might also make a decent exercise game although I haven't put much time into it myself.  When you start getting bored of Beat Saber, just get into downloading custom songs and it'll be tons of fun all over again.
• (When you're wearing weighted gloves, it also turns any game where you're often holding your hands out into a bit of a weird endurance exercise -- archery games like In Death, rock-climbing simulator The Climb, or the slow-motion action game Super Hot.  But although this can get tiring for your arm muscles, I'm don't think it's really good exercise since it doesn't get your heart pumping.)

As someone who plays lots of both ordinary videogames and VR games, I think a big misconception among players of non-VR games is that, since VR looks so immersive and all-encompassing (literally a box strapped to your face), it would therefore be extremely addictive.  In fact, VR games generally seem much less addictive than normal videogames.  VR games tend to be much shorter / smaller in scope than the most popular non-VR games.  And the fact that I'm moving around doing things (plus wearing a slightly-uncomfortable headset the whole time) just naturally causes me to want to switch things up and move between different activities more frequently, rather than sitting down in front of a screen where it takes a bit more mental effort to stop playing and get up to do something else.

In light of that fact, and in the name of encouraging you to buy a Quest 2 and use it mostly for exercise, here are a couple of non-exercise VR games that I figure LessWrongers might enjoy (skipping over some popular stuff that already appears on internet best-of-Quest lists).  None of these games are more than about 5 hours long, per my point about VR games being mostly short-and-sweet:

• A Fisherman's Tale -- a delightful, thoughtful game about recursion and symmetries.
• Shadow Point -- if you, like me, are in love with Braid and The Witness, Shadow Point feels a little like a VR fan-game inspired by those games' aesthetic.
• Virtual Virtual Reality -- a funny, Portal-2-esque experience that explores different mechanics while touring you through a bunch of comedy skits intelligently parodying different ideas about cyberspace.
• (There are also bunch of really fascinating VR games on PC, like "4D Toys" about the physics of 4-dimensional objects, "Hyperbolica" about hyperbolic geometry, and "Paper Beast" (a beautiful game about ecology and physics simulation), which unfortunately don't run natively on Quest.  Instead they require some complicated/finnicky setup to connect to a gaming PC to play.)
• Rez Infinite / Tetris Effect -- entrancing, relaxing, colorful games with nice music.  Nice for taking a short break between workout sections.

I want to echo the warning to slowly ramp up the effort level in Thrill of the Fight. It was natural for me to slip into a competitive gaming mindset, like any game. Turns out even 15 minutes of maximum effort physical activity can leave you hobbled and limping for days. 

You will probably end up buying a bunch of comfort upgrades for the Quest 2. My personal setup: AMVR Touch Controller Grips, an upgraded strap (highly dependent on your head shape - Kiwi or Bobo are popular options), 3D printed magnetic prescription lens inserts that use $8 Zenni lenses, disposable VR covers, a sweatband, and box fan or a ceiling fan in the room. The fan is for sweat but I have also heard it reduce motion sickness, for people susceptible. 

Beat Saber gameplay will train you to use more efficient minimalistic wrist movements to maximize your score, but I suggest at least occasionally reversing that entirely and doing full body/arm swings. More like a tennis or sword swing -- put your hips and whole body into it. Make tons of unnecessary movements that aren't required. Treat it like a dance performance.

I also found VR is less addictive than mindlessly refreshing social media feeds. I constantly feel like I need a break from VR, physically and mentally. I don't feel that way wasting entire days on my Desktop PC.

I sometimes read or watch lectures in VR because I find myself more focused and less distracted wearing the headset. I would love to use this feeling to get more work done, but unfortunately the physical reality of today is that the resolution, comfort level, and software solutions are not there yet. They aren't so far away I can't imagine them in just a few years though. Maybe even less than that -- the Quest 2 only cost $300, but I would happily replace my 3 desktop monitors with a single expensive $2000 headset if the clarity and comfort were there. 

I recommend the quest as the wired setup really does create a barrier to play even though it is less than 5 minutes to setup.

These games are really engaging for me and haven't been named:

Eleven Table Tennis. Ping-pong in VR (+ multiplayer and tournaments):

Racket NX. This one is much easier but you still move around a fair bit. The game is "Use the racket to hit the ball" as well.

Synth Riders. An easier and more chill Beat Saber-like game:

Holopoint. Archery + squats, gets very challenging on later levels:

Some gameplay videos for excellent games that have been named:

Beat Saber. "The VR game". You can load songs from the community library using mods.

Thrill of the Fight (boxing):

If you buy a VR (especially if it's an Oculus Quest 2), here's my getting started guide

I also recommend trying Supernatural on Quest 2. It’s a well-polished app deliberately designed to give you a good workout. I have done it once a week for 6 months and have had a good experience.

I wear a 30lb weight vest when doing these workouts to make them more effective.

Personally I listen to podcasts or audiobooks while I workout to make it interesting, in addition to hearing the music from the game and the occasional comments from the recorded instructor.

I bought a Meta Quest headset two weeks ago based on this recommendation, and I completely agree. It is a very effective way to motivate myself to get exercise. The Thrill of the Fight is particularly effective for high intensity exercise/interval training. I normally don’t like interval training, but when someone is beating you up, you have to react! I previously thought my max heart rate was around 190, today I learned it is at least 205!

One potential downside I see, it that TOTF is violent in a realistic way. Normally, I don’t worry about this in computer games: I don’t think that clicking the mouse or pressing some keys, is likely to translate to anything in the real world. However, in VR, the actions you take to hit an opponent are exactly the same as you would in the real world. So for the first time, I have been worried if a game could make me or others violent. This can of course be solved by simply playing other games.

A more general failure mode of VR exercise is to overestimate how much exercise you get when playing more relaxed games such as Beat Saber. Due to the headset, the sweat to exercise ratio is higher than for example running or biking, so I sometimes think that I have been exercising more than I really have. This is the opposite effect of swimming, were I don’t notice any sweat, and so tend to underestimate how much I have exercised.

The strap on mine broke (actually one of the plastic buckles). It looks like (better?) third-party alternatives cost about as much as a replacement, but I don't know which to choose. Any recommendations?

I get tired and I sweat, especially in a specific intensive game (TotF)

When I read this part I wanted to know: What is TotF? Changing it to:

I get tired and I sweat, especially in a specific intensive game ([Thrill Of The Fight])

would fix this.

I love Thrill of the Fight. Gets me super exhausted with my muscles sore. 

I saw the title of this post and thought of ToF right away! I was an amateur boxer for a year and had a few fights and thought ToF was an excellent workout, and something I’d incorporate if I was still boxing (and if VR didn’t make me sick as a dog).

I guess it would be dangerous to do VR on a treadmill that wasn't purpose built for it but if a good way to do it was found you could make an actual run and gun game instead of standing still like in pistol whip.

I think there is great promise here. So many overweight people don't work out, because they just don't identify as a person that would go running or to the gym. Developing exciting (addicting?) VR games that ease overweight people into work-outs could be an interesting cause area!

Interesting. Makes me consider getting one. Not sure which one to get though.

I was considering waiting until Apple’s headset is out, but it’s going to be quite expensive. I’d only pay that much if I were to release software on it.