Sorting by metascore
It would be neat, maybe as a premium feature, if Dig could scrape rating information from places like GameRankings, Metacritic, IGDB etc, to allow sorting by rating. That way you could browse the most popular or most critically acclaimed games of each system with ease.
I know that there's a custom rating system currently, where people using Dig can leave their ratings, but that will take a long time to populate. Until there's more data there, scraping external sources would be best to get good results.