I guess my most dramatic cel would be Aichan 
calling out to Youta while she is tied to the 
metal cross, while Youta is trying to make his 
way through glass to get to her to prove his love.

my other close ones I guess would be my set of 
cels from the Last Unicorn, since 3 of them are 
from when she is transforming into a unicorn from 
human in order to save them all at the end of the 
movie. 
http://aimee.wyvernweb.com/images/cels/gcuni.html

my favorite though isnt from anime, its from the 
Secret of Nimh when Mrs. Brisby is reading the 
amulet from her dead husband, while Nicodemus 
holds the chain. "you can unlock any door if you 
only have the key"
http://aimee.wyvernweb.com/images/cels/amulet.jpg