<p>What is your favorite bug/issue tracking system? And why?</p>

<p>(Please answer this question only if you have used at least three different <a href="http://en.wikipedia.org/wiki/Bug_tracking_system" rel="nofollow noreferrer">bug tracking</a> systems for quite a long time. And please mention these systems as well.)</p>

Bugzilla
is not too bad.
Bugzilla is very adaptable to various situations. Known uses
currently include IT support queues, systems administration
deployment management, chip design and development problem
tracking (both pre-and-post fabrication), and software and
hardware bug tracking for luminaries such as Red Hat, NASA,
Linux-Mandrake, and VA Systems. Combined with systems such
as
CVS
, Bonsai, or
Perforce
SCM, Bugzilla provides a
powerful, easy-to-use solution to configuration management
and replication problems.
Bugzilla can dramatically increase the productivity and
accountability of individual employees by providing a
documented workflow and positive feedback for good
performance. How many times do you wake up in the morning,
remembering that you were supposed to do something today,
but you just can't quite remember? Put it in Bugzilla, and
you have a record of it from which you can extrapolate
milestones, predict product versions for integration, and
follow the discussion trail that led to critical decisions.
Ultimately, Bugzilla puts the power in your hands to improve
your value to your employer or business while providing a
usable framework for your natural attention to detail and
knowledge store to flourish.