Better client management?

Hi there I work for a small IT contacting company and before I got here they had set up an access database for tracking their clients network information (they have a separate program for all the financial stuff). What I was looking to find was something better as everyone has expressed....well hate for the current set up. What have you guys used in your respective fields to track client network info? As a side note we are also looking for a better knowledge base software as well so if you'd ever used one that combined the two that would be amazing.