Humble Weekly Bundle: Simulators 2 $1/$6/$10
Pay the given tiers to get games in that tier and below. All games have Steam keys and some are DRM-Free.
$1 (minimum for Steam keys)
Personally I'd only go for the $1 tier as Tropico 4 has been bundled to death. However, they claim the ETS2 DLC is exclusive to this bundle so you may want to pay more if you're a completionist but then you're missing out on a lot of other DLC.
Another thing to note is that Out of the Park Baseball 14 can no longer be purchased on Steam.