I'd like offer a small tip to anyone who likes to use nice looking cover art for their emulators and libraries.
IMDB has clean, high-resolution cover art without messy labels for just about every game ever made. Even obscure titles only released in certain regions. If you simply do a google image search for "game imdb" with your game title of choice, it'll most likely appear right away, in .png format.
Likewise, if you want something more compact, IGN has high-res perfectly square images of almost every single game, just do the same search but replace IMDB with IGN. Some might be in .webp format so you might have to convert them if the emulator doesn't recognize the format.
Here's a cover from IMDB...
...and here's the same game from IGN:
Another cool thing, is that the fancy "tall" IMDB covers are available for many games that weren't originally in that format:
IGN version:
Hope this helps you make your libraries even better looking!