www.emudeck.com

This is the one I use, you’ll need to go to the website in desktop mode, download the .desktop file, copy it to the desktop, and run it. Then just follow the instructions.

You can choose what emulators to install. You’ll need to acquire game roms elsewhere online, and then put them in the appropriate game system folder. A few of the more modern emulators will require bios files or things like that to work.

It takes a little setting up, but once you’re done the games will show up in your steam library looking like native games.