Let's play "Count the operating systems in my household"! I'll start:

- Windows 10 Pro on 1tb drive in desktop
- Windows 10 Enterprise VM on desktop
- Ubuntu 18 VM on desktop
- Ubuntu WSL on desktop
- Ubuntu 18 on seconds drive in desktop
- Manjaro on Cheap laptop
- Manjaro on old, expensive laptop
- Windows 10 Pro on new expensive laptop
- Windows 10 Enterprise VM on new expensive laptop

Just realized I have no dual booters :o

Windows 10 Home on desktop, CentOS on laptop/server thing

If we're including everyone's systems in the household:

Arch Linux on Dell laptop

Another Arch on Lenovo laptop

Manjaro on desktop

Windows 7 on Asus laptop

Windows 10 on HP laptop

Another Windows 10 on another HP laptop

macOS on Macbook Air

(The Linux ones are me, Windows 7 is my brother cause he didn't like 10, W10 ones are my dad, macOS is my mom)

Those I know of:

Debian Buster (Laptop)

2x Debian Jessy (BananaPi and Raspi)

DD-WRT (DLink Router)

2x Raspian (Raspi)

Armbian (Odroid HC1)

Windows 10 Pro (Laptop)

Windows XP + Debian Wheezy (unused ancient Desktop)

Windows XP + Debian Squeeze (unused ancient Laptop)

Android 2.3 (Ancient Samsung Galaxy S Plus, only used as audio player without internet access)

Android 3 (unused ancient Samsung Galaxy Beam)

Android 4 (Samsung Galaxy Note 10.1)

Android 5 (Samsung Galaxy S4)

Android 7 (Samsung Galaxy S7)

And not in my household but also under my administrative responsibility:

Debian Stretch (Laptop)

Android 5 (Samsung Galaxy S4)

Android 8 (Samsung Galaxy Tab A)

Raspian (Raspi)

That is quite a mix of OS. Interesting, I wasn't aware of such a big bunch.

Dual boot Win10 / Ubuntu on a Lenovo Legion Y520.

Also, if you're thinking about buying a Lenovo : just don't.

Debian
Mint
Win10 (ew)
Win7
Android x4
iOS x? (Off, unused)
MacOS

I have:
Windows XP machine,
Windows 7 machine (2 pcs),
Windows 8 machine,
MacBook (old one),
Ubuntu Mint (rasPy),
Win XP (VM),
Ubuntu (VM) (2 pcs),
Kali Linux (VM) (2pcs),
Arch Linux [Didn't get it to work :/],
MS-DOS [USB]
Android (4 pcs)
IOS (3 pcs)

Windows 10
Windows 8
Windows 7
iOS (3 phones, 2 iPads)
Ubuntu 18.04 LTS (1 laptop, 1 server)
ChromeOS (2 Chromebooks)

I think that's all

Don't forget:
The RTOS in your microwawe
The RTOS in your car ECU+infotainment
An Openbsd-based os in your tv
An Openbsd-based os in your ps4
Android in your phone
Windows 98 in your xbox one x
Minix in your Intel ME hidden core

@chaoticdenim I don't know the Lenovo Y, those are the Yoga tablet style thingies,right? But the higher prized usual laptops like the E or X series are really good hardware. I have several E series for more than ten years, and they're ok.

I don't like the cheaper ones like the Ideapads, you feel the low prize.

4x - Windows 10
5x - Android
1x - CentOS
1x - Ubuntu 18
1x - Debian

Arch Linux + Windows 10 Education dual boot on my desktop
Arch Linux on my netbook
Arch Linux ARM with Kodi on a Raspberry Pi 3 as media center
Debian 9 with OpenMediaVault on a RockPro64 as NAS

Ubuntu Budgie 18.04
Windows education portable
Android 9
Android 8
Centos 7
Centos 7
Raspian

- Desktop: W10 (cuz Intel+Nvidia, learned that lesson the hard way.. don't buy hybrids if you want to run Linux on it)
- Laptop: Arch Mate (btw I use Arch 🙃)
- 3 virtualization servers with Proxmox
- 3 remote servers with Ubuntu 18.04
- about a dozen containers on the virtualization servers with Arch and Ubuntu 18.04 mainly
- 2 phones, both Android 9
- a tablet with Android 7
- 4 Raspberry Pi's, one of which is active as a mediacenter running Raspbian Lite + Kodi. Another one is a pending project for wardriving, probably that'll be using Raspbian Lite as well.

Maybe I should reduce the amount of devices in here 🤔

@xzvf
KDE neon
Kubuntu
Pop os
Debian
Centos
Fedora
Linux mint
Android
Lineage (Android)
Proxmox (debian)

I don't own any other 'smart' devices.

3x Arch (Main), 1x Linux Mint and 1x Xubuntu (both actually unused), my Father's on Linux Mint

Please don't have me count the OSes on the routers/switches...

No Windows/MacOS though :D

@ddephor it's actually supposed to be a gaming laptop. It's good except that I've had a shitton of problems in just 1 year of owning it

Trisquel (My machine)

Linux Mint (Wife's Laptop)

Debian (My laptop)

Raspbian (on a pi)

Debian (servers)

FreeNAS (HP Proliant Microserver)