>>725355410
Most.

I have a library of 500+ steam games that I don't really own, but the majority of my games are in my retro handhelds.

>Anbernic RG 34XX
Plays anything from Game Boy to PS1.
Granted, that's at a 3:2 aspect ratio because it's a GBA clone, but it doesn't bother me.

>DS Lite
R4 Cart. I gave it a 128GB microSD card and tossed the whole USA-based ROM list onto it.

>New 2DS XL
Modded the fuck out of it.
128GB SD card with every 3DS game, a few DS games that I wanted to keep as a "Favorites" list since the DS Lite's R4 was cluttered, and homebrew games like Super Mario 64's decompilation and Sonic Mania.

I also have ROM hacks of the DS and 3DS pokemon games, the English translations of Love Plus & Battle Network Operate Shooting Star, and GBA games I put on it through Super Injector so they'd run native.