The truly great things about Blade Runner, in no particular order.
1) The music by Vangelis. The soundtrack CD is still being sold after all this time, and has had one or two revisions with additional material.
2) The use of the Bradbury Building (1893) set. It is one of the more famous science fiction sets and beloved by fans. It was designed by the grandfather of science fiction and fantasy “superfan” Forrest J. Ackerman. Marvel Comics has an office in the building.
3) The Los Angeles cityscape. It passes the “travelogue” test of a city so interesting that you would be entertained just traveling around it as a tourist.
4) The 1940s costumes and hairstyles. While done to support the ‘noir’ feel, it also signaled this was the style of the wealthy and powerful.
5) The dissonant elements. Things that intentionally broke the mood, that worked to prevent assumptions about the flow of the plot.
Vangelis scoring a sequel is a must. It wouldn’t be BR without it.