I dunno about best, but here is one of my favourites. I actually used a modified version of this in an L5R game years back, and gained some notariety for telling an unclean joke to a cousin of the Emperor
An explorer has been captured by a band of natives, for tresspassing on their sacred burial grounds. He is given the offer of passing their trials of manhood, and becoming part of the tribe, or being put to death horribly. Not having a whole lot of choice, he agrees to their tests.
First, he must walk barefoot over a pit of red hot coals.
Second, he must drink a huge jar of the most powerfull spirit that they brew.
Third, he must pull the rotten tooth from the mouth of a man eating lion
And lastly, he must sleep with the ugliest old crone in the village, and satisfy her.
He's not exactly sure about these tests, but considering the option is death, he figures he hasn't much to lose. He is led to the pit of red hot coals, his boots are stripped off, and off he goes. He sprints across, smoke rising up, feet blistering from the heat. He's screaming in pain by the time he gets to the far side.
Immediately he is handed a HUGE stone jar, with this horrible looking green liquid bubbling in it. He'd almost swear something in it is looking back at him, but he's being commanded to drink, so drink he does. If anything, it tastes worse than it looks, and it burns his throat as he drinks it. His eyes are watering at the fumes coming off it, but he has no choice, and swallows as much as he can, the stuff pouring over his cheeks and eating into his clothes.
Eventually he lowers it, seeing about 4 of everything now. Two natives grab him by the arms and lead him to the lions cave, then toss him inside, and jump back, bracing their spears.
There is absolute silence for a moment, then these horrible roars, and howls, and screams come echoing out of the cave. They last for hours, and eventually silence falls again.
There's movement in the mouth of the cave, and the explorer staggers out. His clothing is torn to shreds, he's covered in cuts, bruises and bite marks, and there's blood everywhere.
He staggers up to the nearest native, half collapsing, and gasps out ..
"Right. Where's this old woman with the rotten tooth?"