I use ZigVersion which was fantastic next to the alternatives when it appeared. Unfortunately it's still languishing at v1.0 status over a year later and looks to be abandoned. It's criminal that in 7 years, OSX still lacks a decent subversion client when Windows users can take their pick. But this does look good!

Also, be sure to check out MAS (http://sourceforge.net/projects/macsvnserver) which provides the easiest method of installing subversion that I've ever seen. Run the app and you've got an Apache server running Subversion :)