I started using Bazaar at work recently for source control. Before that, I was using company-mandated Visual Source Safe. By "using" I mean "not using", in that not using a source control system of any sort is preferable to using VSS. A more broken program than VSS, I have never seen.
Bazaar has the benefit of not having to run any kind of server or have any central repository at all, which fits well at work because I have no machine I could use for a server and no one is going to buy me one. It also seems to work well in a (sadly) Windows environment.
I find that a lot of the commands are more intuitive than something like SVN. A lot of things reduce to filesystem operations and you don't even need a command. Want to remove a file from the Bazaar repository? Just delete it. Want to rename a file? Just rename it. Bazaar figures it all out.
Local commits are another outstanding feature. Something sorely missed when I've used subversion. Bazaar encourages branching and merging, which fits really well with the workflow here at work.
One thing that really did confuse me is
merge. Thankfully it's covered in the FAQ but it's still sometimes not clear when one should be used over another, other than that
update should generally be avoided for my purposes.