I submit the Tex Murphy games. I've played both "Pandora Directive" and "Overseer" (had "Under a Killing Moon", but couldn't get to work - long story), and was amazed at how awesome they were.
Great characters.
Great puzzles.
Great plots.
It was art. An interactive movie - and a good one to boot. Tex Murphy is awesomeness incarnate in a fedora-wearing 21st-century down on his luck private eye.