For me, I have three-four major oddities depending how you count them.
1) I have a monitor stand. It was made for CRTs.
2) I have a Tandy MMS-10 as my primary speakers.
3) I have a Unicomp buckling spring keyboard. With only 101 keys.
4) I have a Kensington Expert Trackball. Stick a cueball in that.

Now why have I chosen these?
1) The monitor stand was useful when I didn't have an extending monitor.
2) The speaker system is just a nice bit of retro appeal and has an internal power supply. No wall wart or barrel jack.
3) The keyboard has been a nice upgrade over random mushy buttoned rubberdome boards.
4) It saves space. I don't have to drag my mouse around like a caveman.

What are yours?

Let's see..

I got a knife sharpening oilstone on my desk, and batteries under the TV that's acting as a monitor...

Under it i have a PS3 and chromebook just sitting there.

I've got a laptop nearby acting as a router that's feeding it internet via 'internet sharing' or something...

Considering only devices that are tethered to a power outlet:

* Two displays. A small TV (720p) and a monitor capable of 1080p.
* Old desktop computer (sleeping when I'm not using it for a game or videoconference) is connected to both monitors (using a DVI to HDMI cable for the connection to the big monitor)
* Old desktop computer is using a USB speaker for audio
* A Raspberry Pi keyboard (basically a USB keyboard that acts like a hub) is connected to the desktop. There's another hub, with built-in wifi, that is connected to the keyboard. There's a mouse attached to the keyboard, and a microphone and webcam (two separate devices) connected to the wifi (via USB, not wireless).
* Separately, a Rasbperry Pi 4 is connected to the big monitor, along with a USB keyboard, USB mouse, and SATA SSD with a USB SATA adapter. (There's no SD card.) I use this device for web browsing and youtube.
* There's an HDMI splitter that's used to connect 2 HDMI devices (desktop and Pi) to one HDMI port on the big monitor.
* The program "barrier" is used to share the Pi's keyboard and mouse with the desktop. (Actually quite a handy program for my particular setup.)
* There's a camera connected to the Pi, but I don't use it, and am thinking of disconnecting it and putting it away.

So, this is definitely a non-standard setup.

I also have 2/3rds of a new desktop; once it's all assembled, I'll need to adjust my setup to accomidate the new computer. (The old desktop will probably not see much use, as it's rather noisy, and the new one should be better for gaming.) That's more than my MIDI keyboard, which has only 25 keys (though it also has some knobs and pads, which you don't see on the typewriter-style keyboards that are standard.)

Edit: Why the low rating?

The joystick plugged into my computer, a Microsoft Sidewinder Precision 2, is approximately 23 years old.

My speakers (Logitech Z-5500D) are babies at only 14 years old.

Upstairs: I mouse left-handed primarily. But I don't do that silly switch-the-buttons thing. My mouse is probably my most-researched component. It's hard to find a properly ambidextrous mouse that also has a sensitivity toggle button, but also works without "the software"*. (*I had to use "the software" once to disable the stupid rainbow RGB it has. I don't understand why people want all their components and peripherals to glow at all, let alone in color changing ways. The toggle is now saved even when I put the mouse into another computer. I do have to use "the software" if I want to adjust the intervals between the sensitivity toggles, but it came with a good default set.)

Downstairs: I have a TV (really bad quality 4K but 55" -- it's the slowest response time in a display I've ever experienced!) I sometimes lay flat (as in screen up) on my table, and bought an approriately-sized plastic overlay to protect it from scratches, to use as a monitor for my laptop when playing RPGs to display digital battlemaps but use real miniatures (well, I like standees). I don't do the overburdened silliness of digital representations/scanners for figure movement/etc. It's just better than printing battlemaps.

Living room: Stupid Dell laptop kept docked and hooked up to the TV refuses to do TV-only output, it only will do mirror (or laptop screen only). So interventions to make that work.

I do have a Logitech Extreme 3D Pro from back before the logo changed. Rarely dust it off, though.

Main PC:

I have 12 case fans in my pc (120mm & 140mm) including 6 matched in a push/pull config on a 360mm AIO radiator. it's very stupid & I did it just because. It's also surprisingly quiet & when I want to blow out the dust I can just max them & watch it fly. All my case fans are mounted with silicon pins & washers so they don't directly contact the case.

I've cut an additional hole in the side window of my case to mount another fan & also cut out a hard drive bay for another fan.

I've spliced 3 different brands of a-rgb together & managed to get them working off of one controller because when I bought them I didn't know they were proprietary.

I run a-rgb strips out of my computer & under my desk.

I chose an older dual chamber case for my build (Corsair Carbide Air 540) because I like having optical drives & don't get the point of glass fronted cases that greatly restrict airflow.

One of my 5.25 bays is occupied by a hotswap SATA hard drive caddy.

2x 1080p displays, one of them is interlaced 3D.

Bartop Arcade Machine:

I built a desktop PC inside it rather than going the Pi route, it's a very tight fit & includes an nvidia 660GTS

It contains a subwoofer

I added side buttons for playing pinball

Illuminated Marquee has interchangable game cards printed on transparent projector paper so they can be swapped out

It has a 5:4 19" monitor for the display & a lightgun IR bar cut into the bezel above it.

It's covered in sprites from games I love all of which I printed on sheets of vinyl & cut out individually before placing them.
USB sockets are routed through arcade button blanks at the back.

Monitor & PSU cable are spliced so there's only 1 plug coming out of it.

It used to be black but I painted it white. It took a lot of layers including primer, a month later they released a white flatpack >_<

It uses gold leaf arcade buttons for the main buttons as they're quiet but start, coin etc are oldschool clicky!

The arcade sticks can switch between 4 way & 8 way without opening it up.

Surrounding Machines:
I have an old server client with a hole cut in it to route a PCI cable through connected to a soundblaster Live! card that sits outside it (it's used for DOS games).

The processor is forcibly downstepped from 1.8ghz for DOS.

It has a 128gb usb1.0 stick containing windows 98 but by default runs off of an SD card plugged into an IDE header with DOS 6.22.

Dell C610 Laptop:
Windows 98 laptop with a massive dock that contains 2 pci slots, occupied with a Nvidia TNT2 & another Soundblaster.

The sidewinder (freestyle pro) controller I use for it has analogue motion control & it works well, I've owned it since 1999.

Misc

I like to use a vertical mouse.

My keyboards are cherry blacks because I love the weight & noise but I use a wireless logitech at night when coding.

I also have a knife sharpening stone & oil on my computer desk ! (& a Paul Chen Bushido Katana behind it)

A boxed, complete copy of Sim Health sits above my pc, I still don't know what it's worth, if anything.... it's awful.

My computer is a laptop.

I have a Daggerfall mousepad that came packed in the box when the game was originally released.

I'm sitting either in an IKEA Strandmond Chair in Skiftebo yellow or directly on the hard floor.

1. I have several (gaming) laptops, and one Raspberry Pi4, in active use. The only desktop PC I have is some over 20 years old PC that I fire up maybe a few times whole year.

2. In most of my PCs (three of them), I use Logitech V20 USB-powered speakers. Yes I have three sets of those nice small USB speakers. In one of my laptops I have bigger Creative Labs multimedia speakers that have more ooomph.

3. On my latest and most powerful gaming laptop (Lenovo Legion 7 with Geforce RTX 3080, 32 GB RAM etc...), the external 32" monitor that it is connected to most of the time is standing on a flimsy CD-holder. I needed to elevate it a bit because the monitor's stand is not adjustable nor the monitor can't be tilted upwards, and it feels it is a bit too low for my taste standing on the desk.

4. My Raspberry Pi4 is connected to my 65" OLED TV in the living room, and I operate it there with a wireless mouse and keyboard like any computer. So my tiniest computer uses the biggest "monitor" in the house. It is connected to the TV because I sometimes watch videos and movies with it too, it is my main multimedia computer.

Two things.

#1 - My computer tower has a horn. Specifically, it is the antennae for the wireless network.

#2 - The keyboard is a MERC Stealth. The best gaming keyboard ever, in my opinion. It has a regular keyboard layout, but there is also a dedicated set of keys laid out for gaming. This means that I have two pairs of QWASED, with one set being extra wide for easier pressing. Sadly, this keyboard is a rarity that can't easily be replaced. I spent $300 to make sure that I would have a spare, and might even buy a third for a $1,000 down the road. The minute I run out of the MERC keyboards, my days of KB & Mouse gaming might be over.

i use only laptops

Quirks like this make me glad projects like pipewire and
Wireplumber exist.
Fair enough, but do any of them do this?

- The desktop unit is hanging under the desk on a sling system so it doesn't take up space or inhale so much dust.
- I got fed up with replacing my mousepad every year or so and got a metal one that I've had for eight years now.
- My keyboard is wireless, the mouse can be run wireless or wired (Logitech G700s) but my headphones are decidedly wired (sound quality, no iffy BT connection, no batteries to charge), so whenever I'm at the desk I'm stuck where I am.
- There's a webcam mounted on the top of my display but it's not connected to my computer - it's just a convenient height and angle so my wife can plug it into her laptop for work meetings.
- There's a second display on the desk but nobody uses it for anything. Should probably do something about it one of these days.

Nothing too much, its user though .......

- Soundbar balancing on a matching set of egg holders.
- A firm belief that an AIO is an integral part of any desktop system.
- A anime figurine (Fate - Grand Order, joan of arc -- bought cheap) to ward off evil dreams

And that is about it