spoderman: Don't know if it's been on sale on GamersGate, but its been pretty cheap on GMG before (I think 75% off?). Probably requires capsule on GMG though.
genkicolleen: Green Man? I've read that they have incredibly invasive DRM... Is that correct? The GG version is DRM-free (happy day!)
Green Man Gaming is a store, like GamersGate; GMG sells games keys which can be redeemed on various game clients, including Steam and Uplay, for example. There is a GMG capsule thingy, which is their own client I think, but afaik, you don't need it to download or play any of the games you purchase from there.