Revision Control

What does /prog/ think of revision control, and what are its favorite and least-favorite revision control systems?

I use svn for everything. Version control is awesome shit when you develop on 4 machines and have even more production machines because it's fucking easy to script automatic testing and deployment tasks.

Not to mention that none of my development machines have RAID'd storage, so putting it in a svn repository sitting on RAID-1 and mirrored nightly to an external backup makes me all warm inside when my HDDs die (too much porn).