What is your most valued air gun gear?

It is hard to pick any one thing, because they are built into systems, each dependent on another. As you astutely noted, the compressor is really at the root of it all, and I LOVE my altaros. Love the accuracy 1st bubble levels w/ trit too, gives you an accurate level day or night. 

Dollar for dollar though my favorite has got to be one my 3D printers. The ability to make durable parts or tooling quickly and accurately in carbon fiber reinforced nylon just solves so many problems so nicely. Second might be my clip on night vision. (which attaches to a regular day scope) Funny enough uses some 3D printed accessories, and runs off 18650s or a regular wall outlet. Somehow pairing seeing in the dark with an almost silent rifle just tickles me.



Good thread prompt by the way!
 
Down and dirty, only actual “gear” being asked of, I’d say the Regman regulator. That thing is an air saver, a big assist in chronograph testing, and a joy to use target shooting while tethered to the tank. If this tread were re asked as what we find to be the best tool used for air gunning, the Regman wins again, as it truly is a tool.

And yes, back to having property to shoot, that is precious, as especially now when asked(ordered) to stay isolated at home, I would go crazy if I couldn’t drive out to a range or find my favorite place to shoot is over populated with other shooters. 
 
@blackdiesel, like a poster previously said the PCP gear is interdependent. I value the gun, the fill source, my SCBAs, the Stikman fill station, etc. These items complement each other towards the end goal... shooting. Can’t use my rig without all the other sundries... I don’t weigh on a more value scale. Because I can’t shoot without a fill source, can’t fill without a “fill station”, can’t store air without SCBAs. That’s what can make this PCP hobby very expensive, quickly. In the powder burner world... it’s “the rig” cartridges and away you go...