I mildly disagree about being able to read the number series out of order. I think you can't get the full impact of some of the characters' actions if you don't know the history behind them. Sure, they're still amusing but they are much more so if you have the background. They really are fun books to read.
I downloaded one of them to listen to on a trip and was very disappointed in the narration. The woman's voice and her interpretation of the characters' voices were so far off from what I had in my head that it was disconcerting. Maybe starting from scratch you won't have that pre-set notion. The one I downloaded was "fourteen" so I was pretty set in my ways, I guess.
In any case -- enjoy!