JUST finding duplicate files/folders

Yes, I did my research. Solutions are dated or otherwise un-satisfactory. Does anyone know of a CURRENT app. that will find duplicte files and folders (preferably by name, not necessarily size) and list them without immediately sending something to the trash? What I need it for is this: I have an external hard drive that I've manually backed things up to over the years, and there are different "versions" of the same files. I want to get rid of the older ones and keep the most updated ones. Does that make sense? If you need more info, ask. Anybody got an idea?