Valve's digital distribution service Steam is now offering GSC Game World's S.T.A.L.K.E.R.: Shadow of Chernobyl for only $4.99--a savings of 75%. Published by THQ, the post-apocalyptic RPG-shooter was released initially released in 2007. A second entry in the series, a prequel subtitled Clear Sky, followed this year. I would say it's really good bargain!