I would suggest using GG Deals which shows multiple storefronts. Not all of them are trustworthy though.

And for me I bought Guild Wars 1 which is actually cheapest on Steam at a historical low. I also picked up Deadly Premonition 2 and Alice Madness Returns which are also on historical lows.

I would suggest using GG Deals which shows multiple storefronts. Not all of them are trustworthy though.