Not all are retro, but I have:
Famicom, Super Famicom, N64, Gamecube, Wii, Switch, Switch Lite, Switch 2, Sega Mega Drive Model 1 (and Master System Adapter), 32X (attached to a Mega Drive Model 2), Sega Saturn, Sega Dreamcast, PSX, PS2, PS4 (it's just a Blu ray player for nearly a decade now), Game Gear, Game Boy, Game Boy Light, Game Boy Color, Game Boy Advance, DS Lite, 3DS, 2DS, Virtual Boy, Vita, Vita TV, Wonderswan, Neo Geo Pocket Color, Pokemon Mini, PC Engine, various Game & Watch units, Astro City Mini, Egret Mini, and an Analogue Pocket. I also have a Commodore 64 Ultimate on the way but those don't start shipping out until November.
And a modern PC with a 4070ti Super.
If virtual pet toys count, I have a huge collection of Digimon, and also a few Tamagotchi including Paradise. A few other things as well like Pocket Pikachu and TekuTeku Angel.
For emulation, I have a MiSTer FPGA. I put mine into a keyboard case to take advantage of the computer cores. I especially love the X68000 core. But I bought it primarily for arcade games because I hate MAME more than anything in this world.
And I guess the Analogue Pocket kinda counts for emulation too since I use the cores a lot, but I often play real carts on it as well.
In the past I owned an MSX but sold it. Actually I've owned and sold an MSX unit twice. There's some decent games but you're better off emulating.
When I was younger I had the original Xbox. There's no point in owning one of those to day, or any generation of Xbox. Not console warring, and I can get into specifics but I think everyone here already understands.
I also had a PSP before. I was going to bring it back to Japan with me after I visited my parents a while back but it seems to have had water damage so I left it. I can play PSP games on my Vita or just emulate them.
Oh, I also used to have the SegaSonic arcade game but I sold it a while back.
Consoles I want:
At this point there isn't really anything left to get. There are some more Game & Watch units that I would like, but I already have a lot of the fun ones and most of these games can be played on the Analogue Pocket.
I guess what I really want is a virtual pinball table, but I could just make a pinball controller and play on my PC.
It would be really cool to have a candy cab and throw my MiSTer in there, but I don't really have space for anything like that.
I would also like to own the Nintendo consoles that predate the Famicom, but that's just hoarding since I wouldn't really play them. Maybe if I had a museum or something but not for a home collection.
There's some old PC's I would like to own, but it can get expensive fast and depending on the platform hardware maintenance can be a bitch. But in a perfect world I would love to have a PC-98, X68K, and I'd probably hang on to an MSX in that scenario too. But I think what I actually want is an FPGA device that could run all of them instead. MSX and X68K are already covered by the MiSTer, but something is needed for PC98 series.
And not really gaming related but I really want either an NEC PC-8201 a Tandy TRS-80 Model 100. They look like fun, and they would be really cool to put next to my Pocket Computer collection.
And idk if this counts but I've been debating getting a Raspberry Pi 500 and using it as a dedicated Pico-8 device but I probably won't.