Having a projector around can be handy, but it's hard to find one that combines a compact size with decent brightness and HD picture. The UO Smart Beam Laser claims to check all those boxes, and looks cool to boot. Its laser-projected image requires no focusing, and while 60 lumens of brightness means you'll need a reasonably dark room to use it (larger projectors have 10 or 20 times that), it's better than a lot of "pico projectors" that size.
The 2.2-inch cube produces a 720p image and will last for 2 hours on its built-in battery, though you can always just plug it in. Likewise with content: A micro-HDMI input makes it easy to connect a set-top box or game console, and you can connect to it wirelessly as well. There are built-in speakers, but they're almost certainly tinny, like any other small device like this, so plug in a soundbar or desktop system.
The Smart Beam Laser is available for pre-order now for $420, which is a little expensive compared to the competition but still within reason.