The Humble Bundle added the original F.E.A.R., Mortal Kombat Kollection, Guardians of Middle-earth (+DLC) to the list of games. They've also added packages for the free-to-play Gotham City Imposters and Lord of the Rings:Online and a skin pack for the recently released Arkham Origins.
The Arkham Origins skin pack of course is only useable if you ever buy the game, which is available on the humble store at the same price as it is on Steam now ($49.99 US). Alternatively you could just consider buying it at a later date when it goes on sale on steam or just leaving it. The add-in for LOTR:O is the "Steely Dawn Starter Pack" and includes a quest pack, 500 turbine points, and a few other odds and ends. The Gotham City Imposters package is "The Professional Pack" and includes a bunch of weapon option unlocks.
The real meat of the bonus items added to the bundle is the original F.E.A.R. and, depending on your tastes, also the Mortal Kombat Arcade Collection (1-3). Guardians of Middle Earth is a MOBA which was not very well received, but it might be worth a distraction if the rest of the beefier games in the bundle don't give you enough of a backlog as it is.
So pledge $1 or more and get:
Batman™: Arkham Asylum GOTY
F.E.A.R. 2: Project Origin
F.E.A.R. 3
Lord of the Rings: War in the North
Beat the average ($4.70 as of posting) and get the above and:
Scribblenauts Unlimited
Batman™: Arkham City GOTY
F.E.A.R.
Mortal Kombat Arcade Kollection
Guardians of Middle Earth + DLC
Lord of the Rings Online: Steely Dawn Starter Pack°
Gotham City Impostors: Professional Kit°
The Millennium Skins Pack for Batman™: Arkham Origins*
° - an add in for a free to play game
* - DLC for "Arkham Origins", requires Arkham Origins in your Steam Library to redeem. May redeem to your Steam account at a later date if you ever purchase the game.
https://www.humblebundle.com/
More than worth it just for F.E.A.R. and the Batman Games. I am normally not a fan of 3rd person action games but I had a blast with Arkham City; combat system is remarkably good and as a fan of the animated batman series it really hit the spot. Also pretty sure it was Mark Hammil's last gig doing the Joker's voice; been a new guy or two since then.