Euro Truck Simulator 2 is another big one. Some people will go for a higher class of site like Dropbox, but most will use a site like Uploadfiles.eu or Sharemods.com, and every time I open the download on one of those it also opens numerous spam pop ups.
That is so true. I use Adblock, I can't imagine what manner of experience these sites would be without it. I mean, it's one thing to be stupid and click on a shady sounding link, and another to have it open for you.