I have been looking for some decent, easy-to-use bugtracking software lately for one of our projects. My first recommondations were Bugzilla and Mantis, simply because I knew them from the past and they were freely available. But their installation procedures (e.g. Perl, MySQL as prerequisites for Bugzilla) overstrained the sysadmin responsible for setting up and maintaining the server (external staff - to his defense, he had no experience in these areas). Plus I never liked Bugzilla's nor Mantis' user interface.
So I continued searching, and finally found Track+. Originally a Sourceforge project, the licensing model was very attractive (free license for up to ten users), the featureset looked good, it supported all kinds of operating systems and databases, and it came with a complete Windows installer. I did a test installation and had it up and running in ten minutes.
The only prerequisite is an existing JDK1.4.2. The setup package also provides Tomcat 5 as web/application container and the free Firebird database. I only had to add tools.jar to Tomcat's classpath (seems as if the installer forgot about that - otherwise Tomcat's JSP engine Jasper would not be able to compile JSP pages).
We will do some more testing and will most likely move our old bugtracking data over to Track+ if it continues to work that smoothly.