Any match where NicePeter and EpicLloyd are on the same side. There's something nice about seeing them working together.
Vince Offer coming in to take over for Billy Mays after the latter dies. His utter schooling of Benjamin Franklin can almost be seen ~ avenging him - ironic when you consider their real life hostility.
Randy Savage tagging in to take over for Hulk Hogan after Kim Jong Il fires a rocket at him. The video was uploaded a few months before Macho Man died, while the two had been trying to patch things up after their decade long animosity towards each other, one can view this as a sort of burial of the hatchet.
Not to mention that instead of two separate screens, the two dance together on the same screen at the end.
More than any of the other videos their interplay comes off less like a rap battle and more like a heated argument between friends, switching between lines rather than verses and often speaking while standing next to each other. In fact, Bill's Villainous Breakdown at the end could be read as poorly handled grief for losing Steve.
Dumbledore flying away with Gilderoy at the end of his battle with Gandalf.
At the end of the battle between Peter and Lloyd, it looks like Peter is about to pull a Rage Quit and completely end the rap battle series... then, Kassem G swoops in and gives something of a Rousing Speech that convinces him to make a second season.
A meta-example: in the battle between the Wright Bros. and the Mario Bros., the Wright Bros. are played by Rhett & Link, whom Peter and Lloyd have stated were a huge inspiration to them.
The Wright Bros. VS Mario Bros. battle has both pairs of siblings working together flawlessly, showing the true bond between the brothers on both sides.
Obama vs. Romney
Obama's line about having his fist kiss Romney's face comes right after he insults Obama's wife.
Obama: Uh...Let me be clear. Uh...don't get it twisted. We'll see how pretty your face is after my fist has kissed it!
After Lincoln shows up he tells Obama that he wants to like him and yells at him to make good on his hopeful promises. While he just rips Romney a new one, it seems like Lincoln is trying to give Obama some advice with a heavy helping of Tough Love.
Doc Brown coming to the defense of Marty McFly.
Batman shows clear displeasure when Robin joins in to rap with him, before finally interrupting him with a smoke bomb. In contrast, Holmes actively includes Watson in his own verses.
Batman berating Holmes' behaviour towards Watson, telling the detective to let his friend "go home to his wife" and pointing out Sherlock often endangered others' lives.
Santa's elves finally outright stating that they are not Santa's slaves and are in fact the friendly, mystical helpers they are supposed to be portrayed as...with a bit of Smack Talk thrown in, of course.
At the end of their rap, Adam and Eve apologize to each other, implying it was just a bump in an otherwise happy relationship.
Dr. King is obviously very happy to be meeting Gandhi. He says he admires how he broke the British power, and even gives him a big hug during his last verse. Even if the feeling isn't mutual, it's still a sweet gesture.
Even though Gandhi doesn't feel happy meeting Dr. King, he still cheers him on while dancing at the end, indicating they're both friendly enemies.
When Putin comes in and starts rapping during the Rasputin vs. Stalin battle, you can see Rasputin bobbing his head along and swaying in place as if he's enjoying it.
In the third installment of Darth Vader Vs Adolf Hitler, Boba Fett joins in for 8 seconds (all of which were golden) before getting shot by Hitler. Not only was Vader actively enjoying Boba's rap, but shows visible anger when Hitler shoots Boba Fett, and seconds later, kills Hitler, mid-rant, as revenge. No carbonite freeze, no Rancor pit, he finally has had enough, and just straight up Darth Maul's him.
Their video thanking the audience for all their support, to the point they got nominated for a Youtube music award!
Pablo Picasso, portrayed as a Grumpy Bear, lightens up when he mentions his pet dog, Lump.
Ross acknowledges Picasso as a genius even though they're opponents.
JP Morgan telling off Ebenezer Scrooge for his greed and misanthropy, ending with, "Your greed is the curse that's going to tear you apart! What good is a purse, if you're poor in the heart?" Given that JP Morgan was a noted philanthropist in addition to being one of the richest and most powerful men of his time (not to mention the man solely responsible for preventing the united states banking system from collapsing in 1907), while no saint, he was the equivalent of Uncle Pennybags compared to Scrooge.
In Rick Grimes v. Walter White, Rick starts both his verses by telling Carl to stay back, away from his opposition. There is nothing stronger than a father's love for his son.
A bit meta, but the way Peter describes how he and Lloyd write the lyrics for the rap battles shows how passionate they are about what they do.
Peter: Writing is sometimes hard, and sometimes easy. It just depends. It's like—If you're like, a mom, and you have like nine babies. Some of them are labor for 40 hours and some of them are labor for like 20 minutes. They're all different, but we love them all the same.
Crosses over with Funny Moments: Bill Nye is so positive that it seems to hurt him. He compliments Isaac Newton during several of his lines, sings along with one of Newton's segments, and cheers on Tyson when he steps in to take his place.
He's so out of his league against Isaac Newton that it's a profound relief to see Neil deGrasse Tyson come to his rescue. "I got yo' back, Nye!"
A good portion of the Behind The Scenes footage is Lloyd geeking out over "Weird Al" Yankovic, Peter explaining how much inspiration he draws from Chali 2NA, and even Chali talking about how much his son loves Epic Rap Battles of History. The episode as a whole starts to look like a dream come true for them.
Artists Vs Turtles features the Renaissance artists explicitly passing the mic to one another. It's wonderful to see these guys showing care for one another's presences in the battle, especially if you watch TMNT and are familiar with the conflict between their reptile counterparts.
The respective couples in Romeo and Juliet VS Bonnie and Clyde are definitely in love; while it's more obvious with Romeo and Juliet, who spend about as much time professing their love for one another or defending each other as they do insulting the other team, there are some subtle moments for Bonnie and Clyde. When Juliet points out that Bonnie technically is married to another man, it's Clyde who tells Romeo to make her shut up. And when Juliet says that Romeo will do to Clyde's dick what he did to his toe (Clyde cut his own toe off with an axe), Bonnie simply shoots Juliet. All those insults directed at her, and it's the threat aimed at her boyfriend that causes her to stop averting Why Don't You Just Shoot Her?
Also, Bonnie and Clyde feeling bad for Romeo and Juliet's suicides.
In Thor vs Zeus, Thor is outraged at Zeus's abusive behavior towards humanity, and a good portion of his disses are seething with disgust for such tyrannical behavior. Looks like Thor really cares about humanity.
It fits with both his Marvel portrayal and his mythological portrayal, and he briefly looks like the former.
It's also nice to see Loki backing up Thor throughout the battle, despite their often...tumultuous relationship, both in Marvel and in mythology.
Ellen goes on in her second verse about how she likes cute things and making people smile; out of place for a rap battle, but heartwarming nonetheless.
Also, in her first verse, she refers to Oprah as her friend, even though she's battling her.
Spielberg begins his verse acknowledging how he took inspiration from Hitchcock when he was a child. Granted he proceeds to boast how he surpassed him in every aspect, but it's still a nice sentiment.
Similarly, while the other rappers appear annoyed with Stanley Kubrick, Hitchcock breaks his stoic indifference for the only time in the video when he nods his approval and agreement that Kubrick was an artistic genius.
Hitchcock's line that even many Spielberg fans will agree with: "Half your billions should go to John Williams." Especially when you remember that Williams scored Hitch's final film Family Plot, a year after starting to really make a name for himself with Spielberg's Jaws.
Even though Babe Ruth clearly despises Lance Armstrong, he still takes the time to congratulate him on beating cancer.
Likewise, the way Armstrong acknowledges Ruth's talent between bouts of dissing him.
Muhammad Ali showing brief sympathy for Michael Jordan's dead father and his family. Subverted as he was just setting up a shot at Jordan's baseball career.
In a weird way, Teddy Roosevelt insisting to FDR that "All suggestions have merit."
Bill and Ted are left devastated after hearing Lewis and Clark's second verse which disses them completely, telling them that without Rufus they'd be useless. They start their own second verse doubting their own abilities and asking themselves what they can do. Then Rufus himself drops by and answers "Be excellent", making them so happy that they proceed to deliver a, shall we say, most excellent verse.
Meanwhile, Lewis and Clark's relationship with Sacagawea is also heartwarming in a different way. If you pay close attention, you can see that Sacagawea appears to be annoyed by the rap battle and/or Lewis and Clark's immaturity - especially when she has to row the boat by herself because they're too busy rapping against Bill and Ted. However, she still fights an angry bear on her own to protect them.
In Eastern Philosophers vs Western Philosophers, Voltaire jumping to Nietzsche's defense, even though they all start arguing immediately afterwards. Doubly so considering Nietzsche disliked Voltaire.
Stan Lee vsJim Henson
Henson is quick to point out that Lee stole quite a bit of credit from Jack Kirby, a man who has infamously gotten very little credit for his creations, is a nice touch.
Stan Lee quickly shoots back that Jack Kirby was his friend, meaning that he didn't purposefully steal Kirby's creations.
Stan Lee and Jim Henson become friends during their rap battle. Stan's second verse is about apologizing for going too far and how much he respects Jim. Jim, in turn, spends his verse accepting the apology and saying that Stan has left a great legacy to the world.
After seeing Jim's horrified reaction when he mocks Mr. Hooper's death, Stan immediately stops and apologizes. Given how difficult the death of Mr. Hooper's actor was for the cast and crew of Sesame Street in real life, that's a thoughtful touch.
The end credits in Jim Henson vs Stan Lee (the Season 4 finale) includes a "thank you" note to several people, including each of the season's guest stars, the ERB Wiki, "everyone on YouTube" and "you".
A minor one in the form of Deadpool's speech bubbles rapping alongside him for one short verse. It's definitely not uncommon for the three of them to be bickering or snarking at one another's expense, but here the "goofy" box quickly jumps to Deadpool's defense when Boba Fett calls him schizophrenic, and the "voice of reason" one wraps up a line in conjunction with Deadpool himself.