This can be extended further, given that more than one of the tournament guests have cited NCS as their main inspiration and all of them watched his videos before they made theirs.
In his Mario & Luigi: Superstar Saga Let's Play Emile mentions that he was always so jealous of the different Sibling Teams in the game as he really wanted siblings himself. But now, Tim and Jon (and arguably Masae) has acts like older brothers towards him. In said Let's Play he doesn't mention being jealous anymore, further implying this being the case.
If something that looks serious happens to one of the guys, the others will sound genuinely worried about them, even Jon.
The guys recorded Super Smash Bros. Brawl at Jon's house and LittleBigPlanet at Chugga's house. Jon is Canadian, which leaves a good distance between the Wisconsin-based NCS and a massive distance from the Georgia-based Chugga. The guys are officially close enough friends in real life to traverse the country just to hang out.
On one of Tim's BreakingNCS videos, a comment war suddenly started up about whether Chuggaaconroy or NintendoCapriSun was the better Let's Player. After the fight started to go too far, Jon left this comment on the video:
ProtonJon: Guys, both Tim and Emile have gone through a lot of shit in their lives, and both have found success and enjoyment in LPing. I understand not liking someone's LP's or thinking one person's a better LPer, that's having an opinion, but saying you hate the actual person when you've never met themselves seems kind of ridiculous, don't you think? All you see through LP's is a filtered version of a person, you don't know everything about them.
Jon made a Formspring post in response to people questioning his apparent rivalry with Chugga. For those who don't want to read the whole thing, it basically says that Jon actually does consider Chugga a good friend, and at one point at Magfest, the former got very sick and Chugga stuck around to help him get better, checking up on him and keeping him company. The final line sums it up amazingly well:
ProtonJon: No matter how stupid our bickering back and forth might be in videos, know that I legitimately like the guy and consider him a very good friend, and watch over him like an older brother would.
The fact that Chugga and ProtonJon treat Tim kindly, even though they're supposed to be competitive.
Not on the TRG channel, but during part of his own play through of Mario Party 2, NCS selects Mario and DK as two of the NPCs and — fairly consistently — refers to them as Chuggaaconroy and ProtonJon.
NCS: They're not really here or anything, it's just... I don't know. I guess I miss them and so I decided to invite them in somehow.
After the Thrown Controllers event, the guys personally invite Diabetus to play Battletoads with them to make up for leaving him out of the Battletoads event in the panel.
At the end of part 69 of their LP of Dokapon Kingdom, Jon said he needed to take a slight break, and Chugga starts whispering into the mic, starting off by saying that he was going to say mean things, but going on to say that he wouldn't do that and then proceeding to give his feelings on Jon, and Tim as well.
Chuggaaconroy: (whispering) Cool, now I can say unkind things about him. (beat) Just kidding, I wouldn't do that. Because I really do think the world of that guy.
Chuggaaconroy: (still whispering) Might be for the best, actually. You're both wonderful people, and I enjoy recording with you both. Every time.
PAX West 2017 is where Jon proposed to Lucahjin. At the Thrown Controllers panel for that convention, Chugga congratulates them as he introduces her.
At the MagFest 2018 Thrown Controllers show, a young boy named Max was chosen to play Game And Wario with a contestant for a Leap of Faith. Even though they end up losing in the end, Jon decides to let the kid be a contestant anyway.
Jon: Who wants Max to be a contestant? (cue thunderous applause from the audience)
Later in the show, a contestant mentions that it's her birthday, so naturally, the entire crowd sings her "Happy Birthday" when her turn is over. Jon ecstatically responds with "This is why MagFest RULES!"
After the Super Mario 64 race at the end of the second day of the 2018 charity marathon, there was a lot of salt flying around thanks to viewers getting way too impassioned over the competition, despite it being in good fun. One white-knighter particularly took Jon to task over Masae getting the general majority of donation-induced resets, calling it bullying. Masae, meanwhile, gave said user a gentle reminder that nobody was actually hurt during the race, and kindly clarified that everybody had a fun time in spite of the salt. It's better that you read her full statement on the matter, because it's so full of heart that it's hard to embody it in a simple paraphrasing:
Masae: Uh.. Yeah I'm absolutely, 999% okay. I'm completely over the moon with everything that happened and how much this was able to help a good cause. It's a fun time with my very close friends, and in the end it's just a game. I get salty and upset sometimes, but absolutely not hurt. If anything, ANYTHING ever made anyone uncomfortable, we're all allowed to pull the plug immediately. But we all are in this together and everyone has an incredible amount of respect for each other. We're all friends. I assure you, it will absolutely stay that way. I appreciate the concern, but know that friends generally will know each others' limits very well in these situations... Especially in this group. Try not to let a little salt get in the way of supporting a good cause. Heck, I would do something like this again just for fun. Salt, resets and all. But the fact that we're raising money for a good cause makes it even more worthwhile and amazing to me. So relax, we're all having a blast and are not hurt.
When Jon tells the story of how they met one of Chugga's fans before even arriving at Magfest, then saying how awesome it was that they met her.
During Bowser's Magma Mountain, when Jon lands on a Chance Time that causes the CPU to give all of its stars to Chuggaaconroy, resulting in him winning the game, Chugga's response is to literally hug him.
At one point on Peach's Birthday Cake, NCS describes his time at the convention with the other Guys as "These have been, like, the best three days of my life. I'm not even kidding."
Throughout the series — mainly after the first world or two — Jon is constantly trying to kill Chugga. That's not the heartwarming part. The reason behind this is because Chugga ended up nearly giving him a black eye with a pillow (it was one of those cylindrical pillows stuffed with hard foam, so it hurts a lot) and he's just venting anger. He brought this up in an interview, and stated Chugga's actually a really great guy, and now that he's gotten over the incident he's ready to move on. In the interview he also says Tim is one of the nicest people he's ever met and that he'd really like for Josh to come back and guest star in another LP later on. It does make up a bit for the massive trolling he's been doing lately.
Maybe even gets more heartwarming when Jon says Josh is like a younger brother to him.
During the end cutscene, the Guys' commentary as if they're actually the characters onscreen (Chugga is Mario, NCS is Luigi, etc.) is a bit heartwarming. Knowing them, they'd normally have some satirical and sarcastic jabs at the scene. (Except maybe for Tim.)
In Episode 7 of NSMB Wii, the guys go to collect the third Star Coin in World 4-3. After they enter the room where it's located and see that the Coin is encircled by many other coins in the shape of a heart, the guys give a collective "Aaaaawwww..."
In Episode 9, Jon and Chugga agree they should probably let Josh and Tim get more lives. Probably. They do end up giving them the first shots in the 1UP minigames from then on.
In Episode 4, when Link and Yoshi first appear, Chugga and Jon are the ones playing, meaning Tim isn't able to be the first one to play as Yoshi. When Chugga mentions this, Jon kindly sacrifices his turn and gives the controller to Tim so he can play.
Somewhat heartwarming was a few seconds later, Chugga remarks how "nobody can hurt Tim when he's so happy". Tim then receives damage almost instantly. Chugga's response to this, though likely supposed to be funny, is actually pretty heartwarming too:
Chugga: How dare you hurt him when he's so happy! I will decimate you for that! *kills enemy*
Episode 6 opens with a painful-sounding thumping as Chugga takes a tumble. The other two immediately check on him and are obviously worried, even as he decides to Throw It In!.
In episode 13, Chugga is confused about the "Canadian flowers" and making fun of them. Turns out the flowers he's referring to are poppies, and when he learns about the whole "Remembrance Day" reason behind them, he outright states that he feels bad for mocking them.
From the final (story) episode, Chugga and Tim fight the final boss. After getting a Game Over, Tim decides to let Jon have a go at the fight, saying they should continuing rotating. This allowed all three to get a chance at the final fight, with the added bonus of Chugga and Jon working together to finish off the last enemy in the game. It also allowed all three of them to end up with the same turn count, both total and for the episode.
And when you think about it, this also means in a way that all three of them helped defeat Tabuu; Chugga and Jon were fighting, but the final kill was gotten by Yoshi - a character Tim picked and mains. Even when not playing, he lent them his power.
Bowser Land. First turn, NCS gets a hidden block with a star in it. Chugga delivers this line:
Chugga: I think the game just realized that Tim's not playing bad, he deserves to win something.
Near the end of Bowser Land, Jon is debating on whether to steal a star from NCS or Chugganote NCS has 2 stars, Chugga has one, and Jon has a Magic Lamp and was on his way to get a star in the first place. After teasing the two, and the viewers, on his decision, he's about to go for Tim... but changes at the last minute and steals Chugga's star.
However, this may have been part of his plan, as in the end he ended up winning the board because he stole that star; if he stole from Tim, Chugga would have won due to getting enough Bonus Stars and having more coins than Jon.
Jon was glad he won the project, no shocker, but since he stated that he grew up with it, you just had to smile a bit during that statement.
Mixed with CMoF, Chugga being happy to fail so many times in mini-game roller coaster with Wario just to send "D'oh, I missed!" off with a bang, since it doesn't appear in Mario Party 3.
During the Minigame Coaster, the guys frequently help each other out, such as Chugga and Tim helping Jon remember the button patterns in Move to the Music.
Chugga gives Jon a bit of encouragement during the Shell Shocked minigame.
At the start of episode 7, Chugga starts out lamenting that this is the last night they have together; he then gives Tim a White Yoshi to help him further his collection and gives Jon a poison mushroom that actually looks like a poison mushroom this time (the last one was apparently a mini shroom, and Chugga just lied to the internet about being a poison one). He ends it off by letting Tim do the intro.
In episode 9, Jon brought up the fact that, because he tends to dislike people bringing up the old memes that people think he's actually a jerk who overreacts to such instances, bringing up that in these cases he's actually laughing about it and isn't as annoyed by it as the LPs tend to let on.
The Guys help each other out on the challenge rooms. They even cheer on the person currently playing as Kirby and Emile gives Tim a good luck hug before his Sword run. He also attempts to pat Jon on the back after apologizing for making fun of his Wing run, but it looks like he's hugging Tim again from Jon's point of view.
On the Yoshi's Island board, Chugga putting everything he had into supporting Tim at the end, even when Jon looked like he was going to win. This includes giving all of his money to Tim and actively avoiding Jon's properties. Tim wins.
On the Slimenia board, Chugga asks Tim if the fact that Yoshi is a green dinosaur means he's a Slimefoot, one of the creatures from the stories Tim wrote with his sister when they were younger, and which he references from time to time in his videos (especially in Pokemon Sapphire). Tim has a little mini-Squee!, tellimg Chugga that "You have no idea how happy it makes me whenever other people use the word 'Slimefoot' or 'Waterhands...'"
Chuggaa helping Masaeanela out in Mt. Magmageddon. She lost by a hair thanks to a warp space, but still.
The comments on this Let's Play so far have been pretty vicious, with people insulting Tim's playing ability and being disgusting towards Lucahjin due to her gender. The Guys' comments to some of these have been heartwarming as they stick up for each other and put the trolls in their place.
Chugga gave even more presents to the friends on the Runaway Guys. Tim got a Pink Yoshi, Jon got a "Batman for President" t-shirt, and Lucahjin was given a Barbie and Mah Baaaalls.
At the end of Deep Bloober(sp) Sea, Jon and Chuggaa get into a brief, but genuinely heated disagreement due to Chuggaa speeding through the instructions of a minigame Jon's never played before, but they both cool down and apologize.
After the last episode of Deep Bloober Sea, many of the viewers complained that Chugga skipped the text during the last minigame and that Tim didn't deserve to win. Chugga later made a tweet where he admitted that he wasn't the best in the terms of commentary or how he played in that board, but that it's not a reason to act like Tim didn't deserve his victory.
Chugga: I think Tim was playing well and if people think he won due to luck, that's just how Mario Party goes sometimes. Personally, Tim is my good friend and I'm happy to see him win a board. In my opinion, Jon and myself weren't at our best in terms of commentary. I think if anyone had good moments in this board, it was Tim and it was especially fitting for him to win.
Tim sounds quite upset in Spiny Desert when he accidentally made Jon give his stars to Peach via Chance Time. Especially since Jon has been as unlucky in this LP as Tim was in the first two.
On the second to last turn in Creepy Cavern, Tim tries to help Jon get the last star by using one of his Reverse Mushrooms on him, not that it works since Jon wasn't close enough to the star and Chugga used a Poison Mushroom on the last turn to prevent Jon from getting that far. Still, it was nice of Tim.
Though of course he had the ulterior motive that if Jon won, Tim would win the LP by default because Chugga couldn't match his number of board wins...
In part 1 of Waluigi's Island, Chugga mentions that despite his constant rivalry with Jon, he does consider Jon to be the best overall gamer of the three of them.
Once all the boards have been played, the statistics show that Chugga is the winner, but Chugga decides to declare Tim the overall winner due to having the most board victories.
When Jon lands on a battle game space in the last episode of Toad's Midway Madness, his choices are Trace Race or Bowser's Bigger Blast, a reskin of Bowser's Big Blast from Mario Party 2. Chugga and NCS beg Jon not to choose the latter and he doesn't and the others thank him. It is diluted by the fact that Jon himself didn't want to play Bowser's Bigger Blast either.
Do you need just one onscreen moment of Jon and Emile proving their rivalry is just for videos and they're actually great friends? See their dialogue in part 3 of Koopa's Seaside Soirée upon realizing they're paired up for Revers-a-Bomb:
Emile: Jon and I are together!
Jon: (laughing) Oh, dude, we are going to wreck house!
(sound of a high-five)
There are actually several moments throughout this LP where Jon shows enjoyment in being on Emile's team in the 2v2 minigames due to Emile being good at the game, particularly Dungeon Duos, where they refer to themselves as "the dream team".
In the comments, a user asked why Tim kept dying over and over again, and how it felt like he wasn't even trying. Tim would respond to the post by explaining obtrusive sleep apnea, explaining that at times he would blank out and have "mini-dreams" for as long as 10 seconds at a time before snapping back to reality. Not only did he confirm that the other Guys sat down and actually talked with him about how he should go to a doctor while voicing their concerns, but several other comments have suddenly changed their views on Tim, instead pleading he get help and hoping he's alright. It just shows that not only do the Guys care about each other as friends, the community also cares about them.
Tim: Needless to say, the Guys did notice at a point, and we sat down and had a long talk about it, and they have urged me to go to a doctor about it.
In Episode 15, Chugga reveals that he was originally planning to LP the game alone on his channel, but decided it would better to play through the game with his friends. Even better, what provoked Chugga to say this was the awestruck reaction from the other three to the beautiful level they were currently experiencing for the first time.
Chuggaa helping ProtonJon, NCS, and Lucahjin out as he played the game before. This came in handy in the penultimate episode, where Lucah was the only player standing and was about to beat the Negativitron's second phase but died right at the end.
Tim's speech in the finale about the atmosphere in the room when they were playing, and how he hopes it comes through in the LP, using the analogy of hearing about how and where a band recorded an album.
If you ever want to feel that the three are really good friends, the credits to Big's story has the three all laughing and joking at a long gag about Big's audiobooks being available at various stores until Jon corpses and the three devolve into the biggest mess of giggles at their own stupidity.
At the end of "Happy Halloween, Round 2," Tim has been leading the score for most of the game, although Emile manages to catch up in the second half and stay pretty close. During the final puzzle, Tim manages to figure the phrase out but has to wait for his turn to come up again. Emile's turn comes up before that and he eventually manages to figure the puzzle as well, solving it and netting him the win. Despite winning the board though, he feels guilty about sniping the puzzle from Tim and apologizes for taking the victory from him, saying that he was the real winner. Tim simply tells Emile that there's no need to apologize and he earned his victory.
At the end of "Hollywood, Round 2", Jon utterly dominates most of the game and makes it to the final puzzle, but ultimately only manages to figure out the answer with only a few seconds left, unable to fill it in. Worse, he failed on what turned out to be the MILLION DOLLAR PRIZE. Emile felt so horrible for him that he ended up reaching over and giving him a huge hug, much to Jon's embarrassment.
In a somewhat meta example Emile is playing this game blind however both Tim and Jon are helping him go through the game and at times are surprised at some of the stuff he's capable of. However it is obvious that they want to give him the best time with the game as much possible and opt to help him with certain areas at times. (Although some of them are to help sequence break.)
In the finale, Jon's thoughts on the project are mainly happiness over the fact that Chugga enjoyed the game as much as they'd hoped, and that it's hopefully opened the door to enjoying the rest of the Metroid series. Both Jon and Tim as well express pride in how much Chugga grew in skill over the adventure, them noting the Bomb Jumping in episode two as what set the tone for them to be impressed with Chugga's potential.
In episode 22, Chugga, Jon, and Masae all lose their lives, leaving Tim to finish the level. He makes it to Bowser and scores a couple of hits but falls down a pit. The others congratulate Tim on making it that far.