I have been using subversion for about 2 years and have no complaints.

A few items worth noting:

1. Decent documentation
2. Handles binary files, unlike cvs
3. Performs a 2-way diff to reduce bandwidth, unlike cvs
4. Preserves revision history for copied/renamed files
5. TortoiseSVN is a windows shell extension, so GUI folks can use windows explorer to work with svn.
6. Trac is a nice product that combines repository browsing, wiki, and issue tracking. Try the demo
7. Update I found this book very helpful: Subversion Version Control: Using the Subversion Version Control System in Development Projects