My drupal sites, from newest to oldest:
Gadgets Wanted - Geeks want gadgets. Most sites advertise every electronic device possible. Instead we blog about only the most notable gadgets and toys for geeks with no ads (only product images linking to affiliates). Uses few modules and a slightly customized Green Marinee theme.
Seen on Slash - The best comments ever seen on Slashdot. Only a few weeks old but immediately popular with the slashdot crowd. The best posters get free drupal blogs on the site. Uses standard modules and the slash theme (green by default, users can choose any of the 4 colors which come with the slash theme). I actually find the slash theme slightly ugly and outdated but it's good for aligning with slashdot's theme. slash_blue is my personal favorite.
DocForge - News, articles, and links for software developers. We write and collect articles for programmers, some of which go into the book module. Aggregator2 collects links from popular sources. We maintain a huge index of computer terms using a custom module. Beautiful Friends Electric theme.
Microsoft Versus - My anti-Microsoft blog turned into a book ("Dissecting Microsoft"). The Interlaced theme nicely displays this 100+ page book analyzing Microsoft's business practices and software. It's been up (using Drupal) since early 2003. It was mostly idle last year but recently I've been writing updates. The great and simple book module was the reason I chose Drupal for this site. Using drupal for this site made me the drupal fan I am today.