Some pretty epic threads there!
One that comes to mind is ToastBoy's prediction that Kinect would sell over 20m units. THEY THOUGHT HE WAS CRAZY!
My prediction threads:
Wii U will sell under 40m units (made on 14th September 2012)
PS Vita will sell under 20m units (made on 30th September 2012)
Wii U will sell under 7m in 2013 - I was right