Raspberry Pi 3 Model B
Please Note: This is not the latest model of the Raspberry PI 3. The latest model is the Model 3 B+
The Raspberry Pi 3 Model B is a tiny credit card size computer. Just add a keyboard, mouse, display, power supply, micro SD card with installed Linux Distribution and you'll have a fully fledged computer that can run applications from word processors and spreadsheets to games.
As the Raspberry Pi 3 supports HD video, you can even create a media centre with it. The Raspberry Pi 3 Model B is the first Raspberry Pi to be open-source from the get-go, expect it to be the defacto embedded Linux board in all the forums.