Even better, this revelation takes place in the middle of a fight with their own duplicates, who stand there totally bewildered when their enemies suddenly lose interest and run off.
In the same story arc, real!Sanzo saves fake!Sanzo from real!Gojyo...just because he's not letting ANYONE who looks like him get their ass kicked by the cockroach.
YMMV, but this troper found Gojyo's facial expressions in Goku's body during the RELOAD Blast! body-switch chapter to be just goddamn hilarious.
Likewise, Hakkai going all smile-and-floating-hearts in Sanzo's body is a sight to behold.
Also YMMV, but this troper finds the "moron" half of Koumyou Sanzo's Crouching Moron, Hidden Badass incredibly fun. Especially when he's causing Kouryuu or Ukoku to facepalm.
It's even more hilarious in Ibun when he's Houmei. After pulling the power of all the Sanzo candidates together using the Power of Friendship, in an attempt to save them all from an avalanche, he proceeds to take that power and make a giant snowman out of the advancing wall of snow.
And then there's that time when he was caught naked in the bath house and proceeded to scream like a girl and cover his chest as well as his manly bits. Note that bathing naked together was not uncommon, so it was definitely something they'd all seen before.
The Tokyopop translation of the tournament omake in Reload volume 9. Sanzo getting mistaken for a muscle-man fanboy! Everyone being quite rightly terrified of Hakkai! THE CHAMPION'S VICTORY COSTUME!
In the latest chapter of Blast, Sharak calls shotgun in Jeep as they head out to defend a village. Genjyo's face when he realizes that that leaves him sitting in back—quite possibly in the middle, is priceless.
Also priceless is the moment when Sharak and (Genjo) Sanzo come back from their meeting to find their subordinates speculating on whether or not they're losing their virginity to one another. One can't help but be happy for Sanzo about having a friend to beat the crap out of his personal idiots with.