Pay $1 or more for Hitman: Absolution, Supreme Commander 2, and Hitman GO. Pay more than the average price, and you also get Thief, Murdered: Soul Suspect, and Deus Ex: Human Revolution - Director's Cut. Pay $15 or more, and you get all of that plus Tomb Raider and Sleeping Dogs.
Pay what you want. Ordinarily, these games would cost up to a total of $165, but when you buy through Humble Bundle, you choose the price!
DRM-free and on Steam. Most of these games are available on Steam for Windows. Some are also available on Steam for Mac. Hitman GO is only available DRM-free for Android. Pay $1 or more to get access to Steam keys and Hitman GO.