Oskosh IIRC – you mean where they have all the mustangs pylon racing etc.?
No, pylon racing is at Stead Field, Reno, Nevada.
Oshkosh, Wisconsin is the EAA Airventure fly-in – the largest airshow in the world.
I'm fortunate enough to have been to both, though my first visit to Reno coincided with the September 11 attack & the races didn't happen (everything grounded because of the attacks) & the second visit was marred by fatalities. Oshkosh is simply amazing – so much to see & a fanatastic atmosphere. Well worth the effort to attand if you have an interest in aviation.
Couldn't persuade my wife to delay a trip to NZ to visit my brother & family when they lived there to coincide with the Wings over Wanaka show, though. Can't win 'em all, I suppose !
Airpower 2013 in Zeltweg is the fous of this year's holidays – another great event, and free to enter as well.