By far the coolest obstacle was the Waterfall... the pictures are almost too dark to see it, but on the side pictures that look past the cherry picker, you can kind of see where the water was coming out. This thing ate vehicles, nearly everyone who tried it rolled over and/or snapped their drive train. I've also got some of this on video.
This guy alllllmoooooost made it...
Here's a view of another guy as he started up. The dark streak down the middle of the obstacle is the waterfall.
Same guy, farther up. He didn't make it, but he got close.
Same guy, trying to fall off the wall without rolling over.
From the other side of the Waterfall, here's a guy who made it over.
Diabolically, completion of the Waterfall obstacle required them to go over the other way too, so here's a guy who made it over the front, starting back up the backside.
SNNNNAAAAAP! There goes the drive train...