I think most people would call a dialog driven installer running in a tty a GUI installer. They just don't want to be dumped into bash and told to set up GRUB on their own.

Alpine's installer is the best IMO: you get a GUI style wizard but it's contained in a set of shell scripts (setup-*) so if you need it again you can run it yourself.

OpenBSD is another goodie. Answer a number of prompts and then it installs and configs stuff in one go (no more prompts midway through or afterwards). Plus you can "preload" your answers by referring to a file, good if you admin many machines.