Usually I only write obituary posts for public figures I felt a real emotional connection to, but then sometimes someone dies who is so huge, you can't not. I never read Tom Clancy, but his influence was felt everywhere - I certainly liked the movie version of The Hunt for Red October, a rare Hollywood thriller that required the viewer to pay attention. I didn't care for the Harrison Ford sequels as much, and apparently Clancy didn't either - the Ben Affleck prequel worked better as entertainment, despite PC whitewashing of the villains that made no sense.
His influence on video games was also huge - this wasn't just some author who'd slap his name on to any old thing, but actively collaborated on the high-tech spy adventures known to even a casual gamer.
As contributor Holden Hodgdon puts it, the age of 66 "is pretty young for someone with no apparent drug habits and enough money to afford the best health care." No word on the cause of his death, so I'd like to imagine he went out foiling an international scheme that we'll never know the truth of.