SmartSVN - SmartSVN is a graphical client for the Open Source version control system Subversion (SVN).
TortoiseSVN - The coolest interface to (Sub)version control
VisualSVN - VisualSVN - Subversion plugin for Visual Studio
Xversion - Super easy enterprise class version control.
RapidSVN - CollabNet, Facilitating Collaborative Software Development
Slik SVN - SlikSVN is a free subversion client for the command line.