A few tips and tricks to better scraping games in Rom Collection Browser:
As of this writing, the thegamesdb.net usually glitches and causes an error during scraping. If this happens, change scrapers for the next run; the GiantBomb scraper still seems to be working.
Not every rom file will find the right game. If this happens, choose a unique title that isn’t in your collection, then edit the *.nfo file manually. Even if the file scrapes correctly, you can make changes to the *.nfo file to tweak your library listings. For example, renaming “Zelda II: The Adventure of Link” to “The Legend of Zelda II: The Adventure of Link” or “Super Castlevania IV” to “Castlevania IV: Super Castlevania” to keep sequels with their respective franchises.
Use the Local Artwork scraper to fill in missing or incorrect artwork manually. Make sure the image(s) are in the correct folder(s) and named EXACTLY the same as the rom file that they belong to (excluding the extension, of course). Also, use Local Artwork to add videos to your library listings. I prefer to locate recordings of the games’ original television advertisements, reveling in the nostalgia and casually examining how sensibilities have evolved over time. Arcade games naturally get their attract mode videos.