The inspiration for doing this list, ghost story Dear Esther, recently made the transition from amateur mod to full-fledged retail product on Steam. The creepy atmosphere has always been one of the strongest parts of the Half-Life games, and Dear Esther amps it up to 11. Stranded on an unnamed island in the Hebrides, your nameless protagonist wanders, explores and tries to come to terms with the death of his wife. No combat, no puzzles - just an interactive experience truly unlike any other.

Get Dear Esther on Steam here.