UNetbootin (Universal Netboot Installer) is a cross-platform utility that can create live USB systems and can load a variety of system utilities or install various Linux distributions and other operating systems without a CD.
You can get older ones even like the pi 3,4 for cheap, but they don't play gamecube, Wii etc very well. Be warned they use a Linux os, which you need to load onto a micro SD card yourself. You can find pre built images like "retro-pie" online free tho which makes it easy to setup.