The stealth genre in gaming is one that dates as far back as 1981's "005", and it is one that has been in a constant state of evolution. With technology becoming more and more advanced over time, developers have been able to play with our expectations of the hide-and-seek concept in so many fascinating ways. It's a genre that's seen clear stand outs like Metal Gear and Splinter Cell, but it's also one that is open to a lot of different interpretations. From the pure stealth of Thief: The Dark Project to the way that Dishonored was able to flawlessly mix the action elements with all the sneaking about. The instant tension created by a good stealth game is thrilling, as it reacts to a very core part of our human nature. By throwing a player into a room with some bad guys, then telling them to avoid said bad guys, you can create an experience that will grip them from the start. It's how the games on this list made their mark on the industry, and they've never been better these days. So hit the next button to count down the 20 greatest stealth games of all time.