I read a ton of his stuff in my late teens/early 20's. It was after Jurassic Park, but before all his books became obligatory movies. Rising Sun and Disclosure are real page turners.
I also loved The Great Train Robbery
. A wonderfully underrated film with Connery and Donald Sutherland directed by Crichton.
Its kind of fitting E.R. will be going off the air
He will be missed.