I love heatsinks. It's one of those things that makes the physics of an object very obvious, instead of buried under layers of indirection. Gigabyte's latest Brix GB-EKi3A-7100 barebones PC, spotted by Liliputing, is basically a heatsink with a computer inside it. The fanless system runs a Kaby Lake Core i3-7100U laptop chip, and has support for up to 32GB of RAM and M.2 SSD storage. There's a nice amount of connectivity as well, including Ethernet, Wi-Fi, Bluetooth, HDMI, and USB-C.
The system is really designed for enterprise and industrial applications — there's even an RS-232 serial port for hooking up with microcontrollers. But it would also make a great home theater PC, thanks to the fanless design.
There's no word yet on the price, and you'll have to bring your own storage and RAM to make this operational.