Bossie 2010 winner: Cacti
Cacti is billed as "the complete rrdtool-based graphing solution," but there's so much more to it. Cacti can graph anything, and admins can build their own data collection scripts for devices that don't support SNMP. Cacti is easy to set up and maintain, with easy grouping of graphs in a hierarchical tree format. User permissions can be set on a per-graph basis, so the administrator can easily prevent different groups from seeing each other's graphs. Cacti even keeps graph viewing preferences for each user, so all users can customize Cacti to their liking without affecting others.
The Bossies 2010 index: