What do you want/need from a bug tracking system?
dirtyaura: 1) Easy input, minimum number of mandatory fields (2 is quite optimal: "subject", "steps to produce")2) Fast as hell. It's one of the most used dev tools. (Trac fails in this)3) Hassle-free way to add screenshots, log files, etc. And it should show screenshots inline. (E.g. Trac fails in this)