Free weekend vacation at Disney World, including admission to the parks. You actually stayed in one of the timeshare units they were trying to sell. The presentation was about 3 hours long, and mostly consisted of a high pressure sales pitch full of dubious claims. The salesguys were not impressed by the math.
I think the prizes I've seen are generally in the range of $300-600 cash value. To get it you have to sit through the hardest and most annoying sales pitch imaginable. I did it once. I was never tempted even slightly to buy their scam, but it was so miserable to sit through that it's not something I'd ever do again.
After some negotiation (don’t settle for the first "prize" they offer you) I got a free flight and hotel to Orlando, FL and I used the time to visit the Air Force Missile Museum at Cape Canaveral (at the time, I had a badge that let me get on base to visit the museum).
You do need to be prepared for a hard sell. They are clearly making money otherwise they wouldn’t fly me around the country.