I've always believed that Linux is about having it your way. Being able to customize most of the facets of your operating system is the huge selling point (or would be if it cost money).
Along those lines... I wiped Ubuntu off my machines and put Lubuntu back on in about an hour this morning.
And as far as the fun part of Linux goes, it certainly is the customizability. But it's also the freedom and convenience of being able to wipe the operating system and install a completely different flavor in less than an hour. All the while retaining my data, the user settings, and configuration for virtually all the software that I run.
In looking back at the last two weeks with all the installing, wiping, and installing again... to an outsider it might seem like a lot of hassle. But it was not nearly as bad as one might imagine. As a matter of fact... it was not difficult or inconvenient at all. And I learned a bunch by doing it. I don't imagine that I'll be doing full wipes and re-installs on a normal basis. But it certainly isn't a big deal if I do get the whim.
With every iteration I get closer and closer to what I'm after. And I discover what it is I really am after a little more each time. When it comes to functionality... pretty much any of the setups I've had will do the job. So really it's all just about having something to play with. There are much more expensive hobbies to have.