Editors' note: This post, originally published May 16, 2013, was updated August 23, 2013, and January 21, 2014, with new products.
The new tabletop PC category covers products that are in some ways all-in-one desktops, similar to the Apple iMac, but with the added capability of folding down flat, as in the case of the HP Envy Rove 20. You can also think of them as king-size tablets, for example the 18-inch Dell XPS 18, which is a close cousin to Windows 8 slates such as Microsoft's Surface Pro. These systems combine big screens and big batteries to create a unique experience, with features of a personal computer, a piece of consumer electronics equipment, and even living-room furniture.
That's why I use the unofficial term tabletop PC to describe them. Since late 2012, we've reviewed models from Sony, Asus, Dell, HP, and Lenovo, with second-gen systems already on the way from Sony and Lenovo. The Dell and Asus models are the most hybridlike, with screens that detach from traditional-looking stands. The HP, Sony, and Lenovo models are thicker and heavier, with built-in kickstands that can stand up or at an angle, or fold down flat. All of them function just fine facing straight up from a coffee table or kitchen counter, and I'd expect to see some custom built-in furniture options should this trend take off.
Despite liking a lot of the engineering and extra features in the HP Envy Rove 20, and the lower starting price of the Lenovo IdeaCentre Flex 20, I still gravitate toward the two outliers. The 18-inch Dell XPS 18 is thin and light, and it's the easiest to carry around; the Lenovo Horizon 27 is the most ambitious, with a giant 27-inch display, a custom software interface, and a small collection of included accessories for tabletop gaming. Even better, a new version of the system, the Horizon II, is thinner and lighter, with a higher-resolution screen. It's expected later in 2014, and you can see our hands-on preview below.
Lenovo Flex 20
While the Flex 20's hardware is not particularly high-end, Lenovo's custom Aura software is excellent, and makes the tabletop argument better than anything else. At around $750, this is the least expensive tabletop PC to date. Read the full review of the Lenovo Flex 20.
Lenovo Horizon II
The 2014 version of Lenovo's 27-inch tabletop makes some significant leaps over the original. The body is thinner and lighter than the original and it weighs less -- 15.4 pounds versus nearly 19 pounds last year. The screen gets an upgrade, going all the way up to 2,560x1,440-pixel resolution, whereas the original topped out at 1,920x1,080. Read our hands-on coverage of the Lenovo Horizon II.
HP Envy Rove 20
The built-in kickstand is rock-solid and adjusts to different angles easily, and the Rove also features HP's standard Beats Audio subsystem, more USB ports, and a clever on-demand screen rotation button that keeps Windows 8 from flipping the image around every time you jostle the screen. Read the full review of the HP Envy Rove 20.
Lenovo IdeaCentre Horizon 27
It functions perfectly well as a desktop all-in-one, but to see the Horizon 27 really shine, push the spring-loaded hinge down and lay the system flat on your table, desk, or even the floor. Aura, a touch-centric operating-system overlay, switches on automatically when you fold the system down, and a collection of several custom apps and games is available in this mode, including the requisite air hockey (seemingly the first app everyone thinks to install on a tabletop PC), Texas Hold 'Em poker, and Monopoly. Later in 2014, the Horizon 27 will be replaced by the thinner, lighter Horizon II. Read the full review of the Lenovo IdeaCentre Horizon 27.
Sony Vaio Tap 20
Sony's 20-inch version of the tabletop PC deserves credit for being the first out of the gate, but subsequent systems have done better on weight, features, and price. Also, it has a 1,600x900-pixel resolution that just isn't adequate for such a large screen. Read the full review of the Sony Vaio Tap 20.
Asus Transformer AIO
The Transformer AIO essentially gives you two computing devices. One is an Intel Core i5 CPU base unit that behaves like a standard Windows 8 all-in-one. Lift the 18.4-inch display out of its cradle and the screen switches over to its built-in Nvidia Tegra 3 chip, becoming a giant, 5.6-pound Android tablet. Read the full review of the Asus Transformer AIO.
Dell XPS 18
Thanks to its light weight and portability, the Dell XPS 18 is probably the most useful of the current crop of tabletop PCs, and it's fun for playing touch-friendly games. However, the Microsoft app store doesn't make appropriate software easy to find, and the screen's top coating had too much finger drag to really work for fast-paced air hockey/Pong-style games. Read the full review of the Dell XPS 18.
Looking for specs and pricing? Compare these tabletop PCs head-to-head.