This is an old egg, but it still works now. When I was watching the whole series of Strong Bad Emails, I noticed that every webpage's name is written like this: sbemail#.html. Trying to get to the 100th episode as fast as I could, I wrote sbemail100.html. Now here's the egg:

My web bowser showed a tpical page not found error in Internet Explorer style... I was using Opera. And, after, on the backround of this error, I saw Strong Bad walking in this screen saying that the page doesn't exist. Then, Homestar Runner joins and asks Strong Bad where is the page for a 100th email. The email itself was on sbemailahundred.html. So, there you have it. A fake email page.