I resist the urge to reinstall. Being a dyed-in-the-wool Debianite, there's rarely a technical reason that I *have to* anyway, and I realized a while back that it takes more skill to upgrade most Linux systems than it does to reinstall from scratch. Being decently versed in apt / dpkg is ultimately more useful than knowing the install sequence with my eyes closed.
That being said, I do enjoy a Sunday afternoon spent with a six-pack and a fresh system to build up. Geek for life! Represent!