I've got a question for the forum...

With regards to using rsync as a backup method for the open source version of Zimbra, I've noticed a number of different command-line arguments for rysnc beign used in examples, aside from the typical rysnc -av.

So my question is:

What are the best command switches to use... and why?

OR really:

What are the command switches for rsync YOU use... and why?

Curious jimbo