Season 6: Landau Eugene Murphy Junior giving a comforting hug to Anna Graceman after Anna's elimination.
Jonathan Allen's Season 8 audition was just one long moment of heartwarming. After revealing that he was kicked out of his house on his 18th birthday for being gay, Jonathan nails his audition of "Time to Say Goodbye", and get a standing ovation from all four judges. Mel B even tells him that she was fortunate enough to sing with Luciano Pavarotti, who originally performed his song, and she said he would be so proud of Jonathan's performance.
Howie: "Let me tell you something. You seem like a nice guy, and you have a dream and a talent. With that talent, you can say that we are your family now. Welcome home. We love you, we accept you, and we are so proud that you came here."
Not to ignore the other openly gay tenor of this season: Branden James is similar to Allen in that his parents were not accepting of his sexual orientation, with the difference in that he at least had some support from them. (James' mother did see him perform at his audition.) Since his great audition performance, Branden has reconciled with his mother and father who did felt sorry for the way they've treated him in the past.
In Season 9: Anna Clendening, a guitar player and singer, came on to perform. Hearing she has an anxiety and depression disorder, Howie, having an anxiety order himself, says he knows it can be hard for people to understand how difficult their lives can be and encourages her to pretend she's just in her room to help her cope. After she gives a beautiful performance, he comes on stage to make sure she's alright and hug her.
Speaking of judges consoling contestants, crossdressing comedian Scott Heier from Season 10 completely bombs, forgetting his entire set, during Judge Cuts week after having an extremely successful audition. When backstage in tears, Howard Stern comes to talk to him and give encouragement, telling him that although he may not be ready for AGT this season, to not give up and continue on.
Season eight; after teen magician Collins Key's audition performance, he gets a standing ovation from the whole audience that brings him to open tears, since he had never gotten such an overwhelmingly and unanimous positive response before.
Season 10, comedian Drew Lynch shares the story of his extremely debilitating stutter, caused by a sports injury, how his girlfriend works three jobs in order to support his dream of being a comedian, and mentions that (paraphrasing), the person he was would never talk to the person he is today. After giving a successful performance during auditions, Howie Mandel picks Drew as his Golden Buzzer act, immediately sending him to the quarter finals. In response, Drew falls down on stage in tears, and it's difficult not to feel something for him.
After a successful audition from a music group of high school students, Mel B wants to know about the crush one person mentioned earlier, said person repeats a scene from The Office and brings out a coffee pot which his crush opens with a note asking her to prom, and she says yes.
In a way, Tapeface. His performances after his initial audition always involve judge or audience participation. In fact, the only judge he didn't touch was Simon. This serve to humanize the judges. Also, for the final act, he got Victor Kee, Brian Justin Crum, Ekoe from Linkin' Bridge, and Jon Dorenbos to make a human table and even took a selfie of it. All of his acts are also very funny.