Agile Project Management tools

Few days ago I was looking for some Agile PM tool to try.
After considering few options I've stopped on XP StoryStudio . It seems that few other popular choices are TargetProcess and VersionOne .

While installation came smooth and usage is easy - here are few things that could be useful:

• I succeeded to run it only with SQL running in Mixed Mode rather than Windows Authentication Mode (I'm using Desktop SQL engine).
  To install your SQL in Mixed Mode - use the following command line: setup SAPWD="MyPassword" SECURITYMODE=SQL .
• If you want to check or change current SQL mode - here is how:
  "How to Determine or Change Your Authentication Mode - http://support.microsoft.com/?kbid=322336 "
• If something gone wrong during the installation (one of post-installation tests failed) or you just want to reinstall it - you'll need manually eliminate XPStoryStudio link from the Default Web Page in IIS and delete C:\Program Files\Microsoft SQL Server\MSSQL\Data\StoryStudio.* files.

Does anyone have any suggestions/using experience regarding a PM tool you use?