If you have any Greenman Gaming credit, NOW is the time to use it! Greenman Gaming credit will expire on the November 24, meaning any unused credit will be wasted.
Go to Greeman gaming VIP section for deals.
Example: Rocket League $15 USD, South Park Stick of Truth $10 USD
For Amazon deals, check out the following:
Battlefield 4 + Battlefield Hardline Bundle $25 USD
Titanfail Deluxe digital $8 USD (Note: multiplayer in this game is pretty much dead. Only buy it if you're OK with playing against bots.)
How does the amazon game work? Do they gave you steam key, or they have they own download which you can only download from them?
UPDATE: On product QA, its written Mass Effect Trilogy is for Origin. because only Mass Effect 1 and 2 available in Steam. Not sure about other game tho.