Is this computer for business or gaming? Mainstream desktop computers and all-in-ones are geared more toward productivity for ordinary office tasks, graphics work and more, although the best ones can handle demanding games at playable frame rates. Dedicated gaming computers cost more, but they'll satisfy hard-core gamers who want to play 3D titles on max settings and multiple screens, as well as any office task you can dream up.
Will your computer be on display? If you're going to plant your desktop in your living room, you might want a slim all-in-one or a sleek compact gamer with an Xbox-like design. If your CPU is going to spend its life under your desk, looks don't matter so much.
What kind of display do you need? The best all-in-one desktops come with super-high-resolution screens and sometimes touch screens that are fantastic for graphics work. Business and gaming towers don't usually include a display, so factor that into the price.
Do you want an optical drive? A DVD burner comes standard on most gaming computers; Blu-ray is usually optional. But some all-in-ones, notably the Apple iMac, are no longer available with a built-in DVD/Blu-ray drive. If you want one, you'll have to buy an external device.
Are you a do-it-yourselfer? Traditional tower-style desktop computers are the easiest to work on, with plenty of room inside to add more powerful components in the future. Compact PCs leave little to no room for upgrades, and some all-in-ones are so tightly sealed that only a pro should even crack them open; if you're not a tinkerer, this won't be a problem.
What do you plan to connect to your computer? Every desktop computer in this report has basic Ethernet and USB 3.0 jacks. If you want to add surround sound or multiple displays, check the specs to make sure the computer has all the ports you'll need.
How much data storage do you need? 1 TB hard drives are pretty standard, although base models might come with smaller hard drives. Solid-state drives are speedier, but they cost more and hold less.