I'm a big fan of armoires, shelves and cabinets that also function as desks. They offer a great way to hide away all your work mess and tech when guests are over, and are also ideal for small spaces. On top of that, I think it's just fun to have things hidden spaces at home!
Hemnes: This bureau from IKEA was made to function as a desk and is equipped with cable management to keep your cords neat and hidden. The shelves are adjustable so you can customize your workstation accordingly.
Reese Tobacco Compact Office: What appears to be a set of drawers with a glass top actually works as a compact office system. The drawers can be used for storage of course, while the pullout shelf can hold either a keyboard or laptop. When you're finished working, just push the shelf back in and the system turns into a storage unit.
Huelsta Bookcase and Desk: Huelsta offers a wooden bookcase and desk setup that integrates the two together. The desk can be set up or removed easily so that you can use the bookshelves as a workstation or just simply as a bookshelf.
Linear Armoire with Steel Base: Just like the Hemnes, Room and Board's armoire has a pull-out desk, built-in file drawers and adjustable shelves so you can rearrange your storage to fit your needs. The surface has a natural food finish.
Oxford Hidden Desk: The idea behind the Oxford Hidden Desk is to turn an unused corner and nook into a work area. It looks like a dresser but the top of the desk slides out to turn into a table. Pull up a chair and get to work.