I know several people who have had corrupt projects and, unlike FCP 7, where you have 20 or so autosaves to fall back on, they were completely hosed. Versions should improve that at the very least.
My software:
Pro Maintenance Tools - Tools to keep Final Cut Studio, Final Cut Pro X, Avid Media Composer and Adobe Premiere Pro running smoothly and fix problems when they arise
Pro Media Tools - Edit QuickTime chapters and metadata, detect gamma shifts, edit markers, watch renders and more
More tools...