How do I get a pretty visual diff for svn?

One windows I use TortoiseSVN, best SCM client on the planet.

On Linux the closest I can get is installing meld and running the following subversion command:

svn diff MyFile.txt --diff-cmd meld

The easiest way is to use an SVN client. It will enable additional functionality not available with command line SVN.

On Windows, I recommend TortoiseSVN. It allows integration with third party diff tools such as Araxis Merge.

Similar tools exist on other operating systems which allow you to do the same.