If you're one of those people constantly anxious about your "backlog", then I would heartily recommend not partaking in this newest Humble Bundle offer. You see, it's all about Assassin's Creed games, and they're notoriously long and full of things to collect. If you really want Assassin's Creed games, though, you can get nine for as little as $15 (opens in new tab).
On the "pay what you want" tier there's the three Chronicles instalments (y'know, the sidescrolling ones), as well as the original Assassin's Creed. if you pay above the average, which at the moment sits at $6.92, you'll also get Liberation HD, as well as Assassin's Creed 2 and 3. Pay $15 or more, and you'll also get Unity and Brotherhood.
Conspicuously absent are Revelations, Black Flag and Syndicate. If you were hoping to pick up every Assassin's Creed game in this bundle then you're out of luck, but there's still a fair bit to keep you occupied (even if you happened to pick up Assassin's Creed 3 for free last month). The bundle is available for the next fortnight.