Here is kind how things went for me...
Early 80's Dad got us a Commodore Vic-20 and three game cartridges. We wanted an Atari of course, but this thing was great. I wasn't collecting as I was an unemployed teenager in school.
I was still living at home when I was 19, and had started picking up C-64's (even an SX) and other Commodore games and systems at pawn shops and yard sales.
Then PC's happened. I wasn't a console person, but I did have a Genesis an Atari and something else I got out and played occasionally, but I was a PC Network game guy at the time.
I was using PC's at my job, learned networking, then DooM came out supporting IPX over LAN. By the mid 90's I had several PC's with every Network based PC game I could find. I had DooM, HerEtic, HeXen, TekWar, Corridor 7, etc. All of them, in multiples for however many machines I was running them on. Then Quake Came out. In a year or less I had three modems and phone lines in the Quake dedicated server, which ran 24-7 until 2001.
The Quake era was huge, but Duke Nukem 3D is what REALLY started the broad "collecting"... I started looking at other ways to play Duke Nukem games while waiting on the next expansion and later waiting for Duke Nukem Forever to come out. Someone had given me a PS1 as I wasn't into consoles when they came out, so I got the third Person Duke Nukem games for PS1, as well as the semi-port of Duke Nukem 3D. Time to Kill, Planet of the Babes and Total Meltdown. Great times.
Further down the rabbit hole...
I got way into Duke Nukem games and decided to get Duke Nukem for every system it was put on, in every form. This lead to merchandise. I got every Duke Nukem game/add-on, shirt, memory card, book/manual/guide, store display available, from around the world. This has left me with the largest collection of Duke Nukem items in the world. My game room is Duke Nukem themed.
I built this 8ft Nukem symbol in the floor.
Ok... getting excessive, I will summarize more.
I eventually obtained most every mainstream game console and handheld made, and still do minus a few years. (I don't have an xBox 1, but I do have a PS4.) They are all hooked up and accessible at all times, so it takes up lots of space.
Backtracking a little... when I started "collecting" it was only First Person Shooters or "DooM-a-Likes", and their add-ons/expansions/shovelware. By the end of the 90's it got to be too many, so in my effort to "control" this expansion, I realized how much I enjoyed the box art of the 90's, so I stopped collecting any DOS FPS that wasn't boxed. I just rotated my game boxes from storage to sit on the computers and shelves every once in a while. It looked like this back then...
In the early 2000's I moved to another house and had space. I thought I had plenty of space until I got EVERYTHING I had collected in one space. I am building shelves on the ceiling, racks on the ceiling, and the seating in the room are custom built for storage.
Now I am watching people (like Bill L) end up backing off. I am not sure where to go from here... My DOS FPS collection is at around 400 Unique Boxed games, so it is mostly done, no issue there. Console cartridges and disk based systems I only buy specific games I want to play, and I do I keep wanted lists for console games and have budgets for these things. Right now I only buy special editions or collectors editions of specific games like DooM, Red Dead Redemption II and such... so it is slowed down, but still excessive with over 1000 games. I won't live long enough to play them all at this point. I do track them in a spread sheet and play them mood-based. I few years ago I picked up all the Halo series as I had not played them... great games, I see why they were so popular.
Anyway, I have mostly controlled expansion by limiting purchase to game-room decor' based editions...
Edit: Forgot this section... Plug-N-Play and Modern Mini's... These are an issue as there are so many now and I generally buy all of them. I call this "The Retro Tower of Shame", which has now reached the ceiling. Most of the units are in place in a cabinet for instant access, but still. There are just too many, and I really never had "a plan" on a control point for them. I want them all, but that has become impractical. I didn't get all versions of the Flashback consoles and handhelds, which is a start, but still, this is a point of issue.
This is an older image, and now the stack is literally to the ceiling with spares...
Then I saw the post about the Homebrew for Galaga 2600... this will be my first Homebrew purchase. Am I catering to nostalgia, or I am starting down a road I am already resisting?
We shall see.