TortoiseSVN - The coolest interface to (Sub)version control
SnailSVN - Similar to Tortoise SVN for Windows but integrated into Finder
AnkhSVN - AnkhSVN is a Subversion SourceControl Provider for Visual Studio.
SmartSVN - SmartSVN is a graphical client for the Open Source version control system Subversion (SVN).
RapidSVN - CollabNet, Facilitating Collaborative Software Development
Slik SVN - SlikSVN is a free subversion client for the command line.