commodore 64 DTV
Made by Mammoth Toys, sometimes by Lobster. For those who don't know these c64s are a "system on a chip" designed by the commodore grand-master Jeri Ellesworth. I am sure Jeri included hackability in her design proposal as any mid-skilled solder-hacker can turn the board inside these things into a fully functioning commodore 64.
This example has a serial port, two external joystick ports and a PS2 keyboard connector.