The Pick of Destiny has its moments, but what stands out is when, while wearing the titular pick around his neck, Jables screams a high note into a microphone, which promptly bursts into flames. They call it "Master Exploder" for a reason - later, he even makes a person in the crowd's head burst apart, having literally blown their mind.
The film wastes no time and establishes its tone and attitude in the very first line of the opening song: "A long-ass fuckin' time ago, in a town called Kickapoo..." Then it promptly segues into young Jables' hilarious "tasty jam," performed for his WASP family just as they're in the middle of saying grace before dinner. Chances are you either love the movie immediately or are simply not the intended audience.
After getting a spanking from his dad, having all his rock posters torn down, and being grounded for a week, Jables prays for guidance to a poster of Ronnie James Dio (which survived being ripped to shreds by not being visible behind his room door). And Dio answers in song.
The entire Beelzeboss: The Final Showdown scene, where they challenge the devil to a Rock Off. Which they lose, but through The Power of Rock (well, Jables' guitar) manage to defeat the devil anyway.
Meta: getting Meat Loaf to sing in a movie for the first time in thirty years!! It apparently took a lot of arm-twisting, if only because nobody else would be such ideal casting as Jack Black's father.