I was just in Denver and have two nominations.
My folks just moved to Colorado and live on Lone Tree Golf Club. I played the course half a dozen times.
This is an old Arnold Palmer course that opened in the 80s as a private club and is now public.
My first is the 12th hole - Par 4, about 400 yards from the tips, dead straight. The last 120 or so are completely over water and there is absolutely no bailout anywhere. The green sits hard on the water's edge on 2 1/2 sides.
http://maps.google.com/maps?f=q&hl=en&geocode=&q=lone+tree+CO&ie=UTF8&ll=39.534266,-104.886099&spn=0.004568,0.007446&t=k&z=17&om=1(paste entire link)
The fairway stops about 260 off the tee, taking driver out of your hands. At the end of the fairway is a gravel cart path, then a steep slope down into the lake. There is also out of bounds down the entire left side of the hole.
On top of everything else, it's usually against the wind. Get caught behind a foursome of 25 handicappers and you won't finish before dark.
My second nomination would be the 6th hole on one of the nines at John F Kennedy, which is a 27-hole muni in Denver proper that runs along I-225.
http://maps.google.com/maps?f=q&hl=en&geocode=&q=lone+tree+CO&ie=UTF8&ll=39.653218,-104.858633&spn=0.00456,0.007446&t=k&z=17&om=1(paste entire link)
This is a par-four of about 450 yards, but the fairway stops 220 yards from the tee for a 100-yard wide gulch. The second fairway requires at least 320 yards to carry and it is about 20 yards wide at that point, with out of bounds left (I-225 parallels it) and trees right. There's also a tree which overhangs the landing area of your tee shot.
I played with my older brother, a scratch player, and he had to hit 4-iron, 3-wood. I'm a 5 handicap and I hit 3-wood, 3-wood. We concluded there was no other way to play the hole.