I must say this is one of the BEST questions ever asked!
I collect them, just like one collects shells, rocks and stuff...
I also collect them because they really intrigue me big time and they were always fun for me to look at them.
I also like defective or used lamps mostly gas discharge because there are many possibilities of defectiveness to watch and experiment with.
They also look so GOOD on display shelves!!!!
Since I started joining this page and collecting lights ive learned a LOT more!
I also have been always interested in streetlighting, although I used to be mainly interested in general the POLE & streetlight combined.....I orginally was more into looking at shapes of poles which probably started with me and New York City since I went there pretty often so as a kid in a car in a long trip, that was something for me to look at, random streetlight poles on highways!
Examples:
Truss arms and twin tapereds LI Express way randoms (more of those highway scenes will be uploaded soon)
But later I actually started noticing different styles of cobraheads which was because of different models or brands which I didn't notice as much before! I believe one of my personal favorites back then was the silver GE M-250Rs with remote photocells!