The SANS Institute has been publishing lists of vulnerabilities for a while, and this year's Top 20 is well worth a look. The site says:
This SANS Top-20 2005 is a marked deviation from the previous Top-20 lists. In addition to Windows and UNIX categories, we have also included Cross-Platform Applications and Networking Products. The change reflects the dynamic nature of the evolving threat landscape. Unlike the previous Top-20 lists, this list is not "cumulative" in nature. We have only listed critical vulnerabilities from the past year and a half or so. If you have not patched your systems for a length of time, it is highly recommended that you first patch the vulnerabilities listed in the Top-20 2004 list.
The list might remind you of a fix you have missed, and it has links to more information and fixes.
