Nvidia has announced Nvidia Shield at GDC, the "world's first 4K Android TV console" that is set to launch this May for $199 USD. If you remember the Shield brand has been used before, perviously for a gaming tablet and an all-in-one-controller-plus-screen device.
The new console will feature decoded 4K video at 60Hz, and naturally it'll come with a controller as part of the package. It's also worth noting that the console is powered by the newly announced Tegra X1 chip.
Nvidia Shield will have its own store with around 50 games at launch. Confirmed among them are Batman: Arkham Origins, Star Wars: Knights of the Old Republic, Half-Life 2: Episode 1, Borderlands: The Pre-Sequel, Doom 3 BFG Edition, and Crysis. To find out more, you can browse their official page.