The classic poster for the film, the image used multiple times on other foreign posters. Of note is that this version is double sided - the image is printed in reverse on the back:

This is the very first US Lynch poster to be printed this way.

The double sided is much more rare and valuable than the single sided, often acheiving prices twice that of the single sided:

Also of note is a double sided copy that is signed by Walter Olkewicz ("Jacques Renault"):