Drake and Josh performing "Soul Man" at the school talent show which helps Josh overcome his stage fright and gets Drake another first place win.
Megan proving Drake innocent in "Honor Council".
The "Soul Man" routine in the talent show from the Blues Brothers episode. Now, the routine itself is pretty awesome & definitely qualifies, but add on to this that in the show, Josh had suffered crippling stage fright until this point, whilst Drake only came up with the idea to do the routine minutes beforehand after an acappella group stole the song his band were going to perform.
Megan gets one in "Megan's New Teacher" when she and Drake sneak into the school late at night and sabotage Josh's evaluation.
Megan rescuing Drake and Josh in "Drake and Josh Go Hollywood." Everything that happens between Megan calling the police and when the police finally get there is basically one huge scene of awesome. Made funnier by the fact that Drake and Josh had followed Megan there because they thought she needed their help to get on the correct flight to Denver after they put her on the wrong flight.
In "The Great Doheny", Doheny pulls an insane magic trick that gets the townspeople to think he was killed by being impaled with swords...and then he reveals to Drake and Josh that he had to see them terrified for it to work properly.
Really Big Shrimp: The boys think they are about to be sued for $5 million and sent to prison after Josh switches the crappy remix of Drake's song with the original, but Nick Mateo of Spin City Records tells them that they aren't because the song was such a huge hit that it crashed the server. Followed by this exchange:
Alan Krim: Okay. So these guys just scammed us and you're giving them a major record deal?
Nick Mateo: They had to scam us. Because you tried to ruin a very good song. Which is why you're fired.
Alan Krim: What?! You can't fire me! Me and my wife play golf together!
Nick Mateo: Your wife cheats!
At the beginning of Little Sibling, a guilty feeling Josh tells Drake that he can't lie, after Mrs. Hayfer asks him if Drake was on time. Then, at the very end of the episode when Drake gets put in his horrifying Remedial English class by her, Josh arrives there and tells the teacher that the principal wants to see Drake. The teacher dismisses him, and Drake asks Josh why the principal wants to see him. His response? "He doesn't." The episode ends as they both escape the class.
In Girl Power, Helen, armed with a baseball bat, confronts a group of large football players who had just tormented Drake and Josh, and sends them running.
Helen: Now you and your little hoodlum friends get out of my movie theater before I pop you like a zit!
In the same episode, we have Josh defending Mindy and going off on Drake. Josh gets very few epic speeches in the show, but this...this is definitely one of them. Special mention goes to Josh Peck, whose delivery of the speech was pretty damn top notch for a sitcom actor on a kid's television network.