What is the ONE thing that draws you to (collect) HID light sources or fixtures?

My reason is the light sources. The intensity, colors, awesome bulb shapes, the way they start. The fact that there is a violent electrical storm created inside the arctube. There is just nothing else like it.

So what's yours and is it fixtures or sources? Is it the beutiful shape of the fixture or the fact that it's not something you can find just anywhere? Or maybe the lovely hum of a ballast is what excites you?

E: All of the above.

But primarily the efficiency and the intensity.

Primarily all above,the shape of the lamps,the internals and intensity,my favorite has always been the start-up and warm-up.

Mostly what has been said before but for me I mainly like the internals and the different operating characteristics of each.

Yeah the startup is awesome to watch, so unique between the different sources. I think my favorite bulb shape/size is the BT-25. I don't really care for the E or ED shapes. I think my most favorite is the BT-25 ringtop or cleartop, they just look really cool. Too bad the BT-25 is impossible to find anymore. The BT-28 isn't bad either. I see what you guys say about the gear too, it's kinda cool to open a fixture and see what drives the lamp.