Whenever I download a zipped folder, I usually end up with one folder with a zip and another one without the zip with my files. Since I have the actual folder that I need (unzipped) I guess it's safe to delete the one with the zip on it. Am I right?
As Chris says.... yes you can delete the zipped folder....
However...
Zipping a folder makes it smaller... so if your going to keep one why not keep the zipped one and save a little space on your hard drive. you can soon unzip it again if you need to.