The second Bung coding competition had quite a few entries. The results can be found here, but the ROMs themselves aren't cached:

http://web.archive.org/web/20040906054356/http://defaced.co.uk/bung/GBCodingCompetition/2ndGBCodingCompetition/2nd_results.htm

It would be nice to have all the entries assembled together for posterity.