Annie finishing the spell to defeat the demon in the second film despite her knowing her injury is fatal. she literally gave her life to save the world
[This Troper] always preferred the director's cut version - * boom!* "...I ain't that good."
Ash cutting off his own possessed hand in the film prior to that seemed like more of a "Holy Shit!" moment. His subsequent mounting of a chainsaw to the stump can only be described as "Groovy."
"I'll swallow your soul!" "...Come get some."
Or in Evil Dead II, when he responds with "Swallow this." [Shotgun blast].
The Deadite possessing Ash's love interest decides to taunt Ash by saying "You found me beautiful once." Without missing a beat, Ash comes back with "Honey, you got real ugly."
Ash surviving the pit. He climbs out and starts challenging everyone first in a soft voice then in his BOOMSTICK voice.
"The name's Ash." chk-chhk "Housewares."
Just prior to that: "Lady, I'm afraid I'm going to have to ask you to leave the store."
And then: "Hail to the king, baby."
One CMOA that doesn't go to Ash: Annie, despite having been stabbed in the back, manages to recite the spell to stop the Evil force.
In Army of Darkness, after Ash has put the Primitive Screwheads in their place, he's reclining on a couch getting fed goodies by lots of girls, and Sheila tries to get in his good graces.
Ash: First you want to kill me, then you want to kiss me... blow."
For that matter, practically every line he delivers in both movies was Rated M for Manly.
The initial defense of the castle with flaming exploding arrows. Ash said it best.