Nintendo Entertainment System (NES), part of GameDB.
NES.data.json: All data, structured in the JSON formatNES.data.tsv: All data, structured in the TSV formatNES.release_dates.pdf: Histogram of release dates, stratified by regionNES.titles.json: Mapping of serial numbers to game titles, structured in the JSON format
To my knowledge, it doesn't seem like the NES ROM header contains a uniquely-identifying serial number or game code: just information that's necessary for the actual execution of the game code. However, NES games are very small (the largest cartridge capacity was 1 MB), so the CRC32 hash can be computed quickly. Further, folks commonly compress ROM dumps, and GZIP files contain the uncompressed file's CRC32 hash for validity checks, which can be easily read without recalculating from scratch (e.g. gzip -lv game.nes.gz).