Ability to have your games appear listed as previously played or in alphabetical order.
Allow you to create genre groups and select what goes in where. You can have the standard sci-fi, sports, racing etc. But Mass Effect might not be chosen to go in RPG but fit in action adventure etc.
Ability for you to create your top 10/20 games from what games you have played. You can only select a game you have played, not a demo or viewing a screen shot and getting excited before the game is even out. This way you pick your favourite, it then checks others around the world and tallies up the top 20. Perhaps even have a genre specific chart.