You won't find all the photos and videos the agency's probes and telescopes have ever taken. It hosts only the best of what NASA has ever released to the public, including historic ones like the Apollo 11 moon landing. Even then, the library still boasts over 140,000 searchable files, which you can sort by update date or popularity if you don't even know where to begin.

Some images come with their EXIF/camera data, including the exposure, lens used and other information, while all video downloads come with a caption file. One huge plus is that its interface automatically scales for phones and tablets, so you can mine for NASA gold anywhere you are.