Superhot VR and Half-Life Alix, in that order. Sprinkle in some Beatsaber to taste.
Playing Superhot VR for the first time made me experience actual physical euphoria. I hadn't had that reaction to a new tech thing since I first got a ZX Spectrum as a little kid.
The only downside of starting with these is that it sets the bar incredibly high. But I still recommend it - it's hell of an introduction to a new medium.
I had Quest 3s for a couple weeks but I returned it because I didn't liked it and wanted to buy the Quest 3, but at the end I just decided to wait for the Steam Frame.