Mauricio Guimaraes is a web designer and illustrator from Brazil. His online portfolio at mauricio.art.br demonstrates this in a unique way by creating an immersible environment that shows off his world.
It is not a very complex site, only having 4 sections in total, but it more than makes up for depth with rich visuals. The drawings are detailed, animations smooth, and overall is just down right fun to explore and poke around. Flash is the perfect medium for a site of this nature as the non-linear layout is hard to translate in HTML. Plus, Mauricio avoided many of the things that depress the user experience of a Flash site like music blaring, lengthy load times, and an non-interactive intro screen.
So if you are ever thinking about doing a pure Flash website, take a good hard look at your requirements and make sure the medium supports the desired user experience.