Like Activision's games (especially Call of Duty), Ubisoft titles don't really get fantastic discounts during Steam sales, especially the Assassin's Creed games. I recall the first Assassin's Creed usually costing RM16.50 during seasonal sales, which is the same price that the four-years-newer Far Cry 3 commonly ends up with during discounts. Last year was worst, with AC1 costing over RM20 during the Autumn Sale and Winter Sale (possibly during the Summer Sale as well, but I can't remember) while Far Cry 3 maintained its usual discounted price.
In contrast, you can get AC1 for as low as RM4.50 ($1) on Humble Bundle right now!
Okay, I guess it's a bit mean to compare prices like that when Humble Bundle is about charity, and it's a given that prices will be more eye-catching than even Steam sale prices due to its more exclusive nature. But it's worth pointing out if the Steam sale prices for the Assassin's Creed franchise have always turned you off, although bear in mind that Humble Bundle is offering Uplay keys only.
Anyway, that RM4.50 - or more if you want - doesn't just get you the first Assassin's Creed, but also the side-scrolling Assassin's Creed Chronicles trilogy. Pay more than the RM32.13 or so average ($7.14) and you get the beloved Assassin's Creed 2 and less-beloved Assassin's Creed 3, along with Assassin's Creed: Liberation and the Tyranny of King Washington DLC for AC3. That's 3 of the main titles and a bunch of spin-offs for less than double the amount of AC1's latest discounted price on Steam (okay, I'll stop being salty now).
Lastly, if you pay RM67.50 or more ($15), you get Unity and the AC2 follow-up Brotherhood as well.
2015's Syndicate aside, Black Flag, Revelations, and Rogue are noticeably absent from the bundle. That's a bit of a downer, but ultimately the Humble Bundle is still a pretty good deal. Also, it's for a good cause.