TortoiseSVN - The coolest interface to (Sub)version control
VisualSVN - VisualSVN - Subversion plugin for Visual Studio
Xversion - Super easy enterprise class version control.
SmartSVN - SmartSVN is a graphical client for the Open Source version control system Subversion (SVN).
AnkhSVN - AnkhSVN is a Subversion SourceControl Provider for Visual Studio.
SnailSVN - Similar to Tortoise SVN for Windows but integrated into Finder