The Most Insidious Pop-Up I Have Ever Seen
Well, this one takes the cake:
When it popped under the Drudge Report, it immediately prompted you to install its ClockSync adware software. None of the subtle "Click here" or any of the other fake system update stuff you've seen in other ads mocked on this site. No, this is straightforward hijacking of your Web browsing experience.
Damnation and ruination upon you, Whenu.com. I curse your very existence, and hope the FTC and your local state attorney general act upon your complaints soon.
Update: I corrected the spelling of whenu.