(Engadget does not condone piracy.) Backing up files of games you already own for personal use only is considered more defensible, though, so for that a mobile handheld can be a more user- and wallet-friendly way to play the classics anywhere. Getting emulators to work can be complicated, and accessing the BIOS and ROM files required to play games this way is legally murky. While most are marketed toward those ends, many gamers actually buy them to emulate classic games through software like RetroArch. They aren’t equipped to play modern console or PC titles, but they’re usually more compact than a portable PC, and they can still be used for mobile games and cloud streaming.
These often run Android or Linux and can range from under $50 to $400-ish. Further down on the price spectrum are mobile handhelds like the Logitech G Cloud or Retroid Pocket.