Lots of adventure games for sale on Amazon. Lost Horizon for $2.50 is tempting. Would also like to grab Secret Files 3 to finish the series. No mention of DRM, but I'm guessing the games that don't clarify if they are Steam or Origin can be just about anything and probably not DRM-Free, right?
Right so. If it's not a Key Code, don't bother with Amazon.com games that need to be downloaded, if you are not in the US.
my 2 cents. :)
Amazon also has perfectly DRM free installers. The Mega Drive Classics, Ass Creed, RCT3, Risen, stuff... Once you download the installation files, you can back up the installer any way you want.
Casual titles however can come with Amazon's custom client and activations.