The Andromeda Strain is one of the best Crichton has written - but the movie (1971) seems to have an uncomfortable dependency on the book. Watching it last week gave me the impression that Crichton had written the screenplay - it's almost a page-to-frame transformation. It might be difficult to appreciate it without having read the book, but it's well made, with fast paced scenes. The technology show is of course, appropriate to the times it was made in, but apart from the bulging tube computer screens I couldn't find much else to mark as really dated.
Definitely worth a watch. At one go.