Do you use them? Do you put them in a show case? Do you have them as a collection of rare things, but hidden away in the attic?

In my case, i like looking at the differences between all the various light sources, both bad and good. Today, a 9w Philips SL (2nd generation with the smooth, milk glass 'bell') is lighting my room in its specific overly warm, artifically yellowish color. Tomorrow there might be something else in my ceiling fixture, and the workbench is lit by the 20w 'fat' Caddilac fluorescent.
I don't collect them for the sake of having them, i like to actually use them once in a while. Even if it's a greened out HPL lamp i enjoy to have it light the room once in a while.

I don't own historically significant stuff, so i don't have a showcase with lamps that are just for show, not for use.

So what do you do with your collection?

 Currently , 90% of mine is either in plastic totes or leaning against the wall out back .

Mine is currently hidden under my bed. I don't have proper fixtures to display them yet (I cut them up).
For some reason, I don't like part of my collection away from the rest (maybe intense paranoia).

I keep my collection and fascinations a secret from just about everyone in real life. Most people who come over see a tidy well put together home with nothing standing out on the surface.

Lightbulbs stored on top shelf of linen closet. sorted into 3 cardboard boxes: incandescent, discharge, and LED. Incandescent one is overflowing.
Christmas lights mostly stored in six boxes that are on a high shelf on each side of the garage door. Sorted into categories: mini, C7, C9, lighted garland, novelty lights/speciality.
Exit signs fill the drawers of two large dressers and two night stands in my master bedroom and some spill over under the bed and into the closet. One dresser drawer has tools, 6v SLA batteries, spare bulbs and fuses to repair Christmas lights and exit signs, along with my "play lights" and a special flashlight.

 All of my lighting collection is right out in the open . As I've told people before , everyone collects something !!

@ Cool Beans, you mean to say that you have flat surfaces with nothing on them.?? 
That's an unknown concept here... 

There's a bunch of fluorescent lamps & Christmas lights in the basement, more in various closets, fluorescent fixtures in the attic & crawlspace, & the better ones in a bedroom.
Essentially wherever there is (well, was) a empty place to store them...basically in other words I have far too much crap. .lol.

Honesty would like to sell off some of that stuff (mostly Christmas lights) since I'll never use it all.

Good luck with that, having just seen how eBay are cracking down on some listings... 

Yep true .. I wonder if it'd flag sets of incandescent Christmas lights because they are  'incandescent' ?
But no worries there: I don't do eBay for selling anymore .. ever since they changed that policy where you have to use your bank account instead of PayPal
(even before that it pretty much sucked as a place to sell, in the last couple years before that change the amount of listed items I had that actually sold slowly shrank away to basically zero.)

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I don't do Craigslist(which I believe is just a US thing) for selling because of the flighty people on it.

Oh and FB Marketplace. I won't do that one either (I know you'd get that one because ... FaceBook .lol. )

Nearly all of it is in the loft, including the test rigs, but don’t get used anymore! (I use to use them nightly)!
The only ones I keep in my room are the ones in full time use, (these are all LED/CFL) though.

The majority of my collection resides in my bedroom and closet with some larger fixtures being stored in my garage until I can get better storage for them. A lot of my lamps are there also. Eventually with the more assets I find and collect, I will migrate some to my storage space I have which currently houses a majority of my other hobby, vintage electric fans! A lot of my lights I have in my room are also NOS, so they are in their factory boxes and I sometimes pull them out to run and use.
What do I do with them mainly? well, enjoy them for what they are! not every day someone can say they have a Westinghouse OV-25 Silverliner running on their bed! I also just enjoy the entire idea and technology of HID especially now with the decline of it and the rapid uprise of LED implementation. Another reason is preservation!

my collection is MOSTLY streetlights and I run them in my house for light - right now I am running my R37 with a 175 watt Mercury for room lighting
the fluorescents are mostly stock to keep my lighting in my house working
the street lights are mostly in my living room on the floor
 

They are scattered around my room, in tidy, organized piles. Since it's mostly fluorescent lamps (CFLs in particular), I have them grouped by starting method. I also put the globe lamps in a section together. My incandescent lamps are on a shelf I built above my bed, and part of the linear fluorescent collection is in the supports for that shelf. The rest of the linear fluorescent stuff is on a high shelf near the ceiling of my room. The HID stuff is grouped by the door on the floor, and the fluorescent ballasts are behind that collection on a cabinet near the floor.

Basically, it's tidy.

Edit: I use a lot of them day to day, and most of my collection is for replacements. I don't like to keep lamps which I don't have a fixture for.

Most of my collection is down in my (unfinished) basement in a far corner. I have two shelves of overflowing lamps (not really a rhyme or reason to anything there) as well as boxes which hold my streetlights. Project lamps/fixtures are typically stored underneath my workstation (foldable plastic desk), and test fittings are on top of my desk. Also, all of my boxless NEMA Heads and streetlights are stored near my workstation.

Some of my "quick access" collection is in my room; a couple of GTE Sylvania Energy Pincher 90W lamps, a few fluorescent fittings (limited to 2ft and below) as well as my SBMV lamp. Honestly, a lot of stuff here needs to go to the basement; I just keep forgetting or simply pushing off the task for later.

All of our general-use LEDs (older Feit and Sylvania) are stored in the garage. It's a larger-than-normal storage area than most people have for regular-use lamps, but it's nice having equivalent replacements for older, more obsolete LEDs (take Feit's indestructible BR30 lamps that were recently cheapened).

Well, my collection is split into two parts.
Bulbs (with box) that I have bought from the old stock (around 400-600),
and bulbs (without their box) that I have gotten used (around 300-500),
either from recycling, either from someone, either from abandoned places.
The NOS collection is all hidden in my closet in
6 plastic boxes stacked on top of each other (3 in each column and 2 rows)
and because the retail store has changed the design of this specific plastic box,
I don't wanna buy the new plastic containers because they don't match at all with the current ones.
This has resulted in 2 very big lamp & box mountains on top of each row.
And this has blocked my access 3/5 of my collection. I am planning to get rid of the plastic boxes
and add shelves to my closet to keep the lamps there safe, and easily accessible of course,
and without the danger of the weight of the bulbs on top causing damage.
The "finds" part of my collection is stored in 3 big plastic boxes with wheels under my bed.
It is very practical for me, although I don't like having bulbs on top of each other because sometimes
they get scratched (especially coated bulbs).