Do you use Team Foundation Server, Bugzilla, a homebrew, a shared document, or nothing at all for bug tracking? Let us know by taking this poll.
Different organizations have different needs. The bug tracking tool that a big shop uses may be overkill or clunky for a smaller one. Some developers feel comfortable just using a shared spreadsheet or other similar system; some places just write their own to fit their needs. I've also seen plenty of environments where no one knows what they are doing for bug tracking, other than jotting notes on the back of a napkin.