I used to play these games around 10 years ago or more, and without any other option available I had a second partition with windows 98 as “game station”, somewhere I should still have the original boxes and perhaps I should start to search for them, because now they have (finally !!) arrived on Linux.
Steam client for Linux is becoming richer by a growing number of game titles and now you can see on the game database http://steamdb.info/linux/ that half life, Counter Strike and the newsest version Counter Strike Source have “Game Works” as Linux Status tag.