I absolutely love Fogbugz. I find Jira to be a bloated, complex mess. I've also used Trac and Bugzilla, both were clunky and lacking in creature comforts.
Very much agreed. Fogbugz also has one of the simplest "surface" interfaces. It manages to hide all the complexity, without sacrificing feature, leading to very smooth workflows. Trac, Bugzilla, and JIRA (I haven't used Redmine) all seem to lead a sort of "fragmented" style of use, where you transition between thought modalities, while Fogbugz keeps it very streamlined.
