I've looked at pretty installers like that of Ubuntu and Fedora, and they are all very easy and slick. But whenever I install Debian, I don't really see how much harder it is to use, though it's a lot uglier.

Anyways, what triggered this post is the following tit-bit:

d-i [Debian Installer] is the very first thing many of our users see, and has a huge range of uses, from simple desktop installs to massive corporate deployments; it's unspeakably important that it works well, and it's a testament to its design that it's been able to trundle along without actually very much serious refactoring for the best part of five years now.

-- an interview of Colin Watson

In addition, this tool (or rather, a set of tools) also happens to be rock-solid, and its great reliability and ease-of-use gets admiration from me on each install... I've done dozens, with not one instance of data loss.