I almost always call it just A New Hope in discussions, regardless of which version I’m talking about, just for simplicity’s sake and to distinguish between the film and the franchise as a whole. Though sometimes, talking with my parents, I’ll call it “the first one” or “the original” since they grew up not knowing the subtitle.
I kind of like “A New Hope,” because of how the titles of the OT mirror the titles of the prequels. Episodes I and IV both have a title referring to an emerging individual who will bring about change in the galaxy. Episodes II and V both refer to an attacking army or military power. And Episodes III and VI both refer to the back-and-forth shift in power between Sith and Jedi.