I use SVN in the FPC project, and also at work.

In the past I've used SourceOffSite, SourceSafe, Jedi VCS and CVS. I still like SVN best.

Specially if with 1.5.x merge tracking will get less problematic.

The only wishlist item then is to be able to remove a file entirely from the history (e.g. due to copyright disputes). Now you have to export the SVN db, postedit the export, and then reimport.