Dragon Ball Z, Vol. 18: Gohan vs. Cell (Dragon Ball Z, #18) | 
pick9/10:
The power of Gohan is unleashed, and holy cow is it incredible! The fact that this young Saiyan is stronger than Trunks, Vegeta, and even Goku is unheard of, but I cannot wait to see how his fight with Cell continues!
I also find it really neat how much Piccolo shows his love and concern for Gohan when the fight begins, even more than his own father does.