Heartwarming / Bill & Ted Face the Music

• After Bill and Ted arrive in the future with Kelly, they walk past their iconic phone booth from the first film with a holographic copy of Rufus stepping out. Even though it's a recording, when they continue to follow Kelly, Ted flashes a hand wave goodbye to him before continuing on.
• Billie and Thea's awestruck reactions to meeting Jimi Hendrix and Louis Armstrong. It's like they're staring into the face of God.
• Just like Beethoven in the first film, Mozart is entranced by seeing how musical instruments will evolve and eagerly agrees to join the band without a single word needed.
• Bill and Ted meeting their much older selves from 2067. Equally funny and touching, particularly the older versions describing the current ones as being "good boys".
• When they find out that Billie and Thea are dead, Bill and Ted don't hesitate to kill themselves and go to Hell to bring them back to life. Even going as far as to destroying a USB drive with a copy of the song needed to save the world in order to do so, showing their dedication to their family first.
• Despite multiple futures where Joanna and Liz search for a reality where they are happy with Bill and Ted and not finding them (leading to their divorce, Bill and Ted's daughters not speaking to them and Bill and Ted in a downward spiral), Joanna and Liz arrive just before the song at the end to tell Bill and Ted that they are happy with them in THIS reality.
• When Bill and Ted arrive in Hell, Louis Armstrong sincerely compliments the two for raising such good daughters.
• The climax of the film, where the girls, with the help of their parents and the historical figures they've assembled, manage to write and perform the song that unifies humanity.
  • What makes this moment even sweeter is how it's done. Through various time-travel shenanigans, Bill, Ted, Elizabeth, and Joanna manage to distribute musical instruments all across time, getting everyone to join in and play. So in essence, it wasn't the song specifically that mattered, but the fact that everyone was playing it together.
  • While everything else is going on, Kelly's mother tells her "Your father would be so proud of you." A perfectly understated tribute to George Carlin.
  • You might imagine that, given the song being played across time and space, people in the past would have remembered Bill and Ted showing up to tell them to play a song, so the mystery shouldn't have been a mystery. But considering how time travel works in the films, going 'infinite' would just take... infinite time. So instead, what is really happening is B&T and family are inspiring people across time and space to play music. Meaning that first time you played a song you were proud of or maybe the first time you strummed your guitar or that time that one person gave you an instrument and inspired you to play... you were helping to saving reality.
• The post-credit scene where old Bill and Ted in the far future, crotchety and weak, perform one last guitar solo together. After all these years, it's touching to see those two rock it out for the last time.
• The fact that no matter how awful Bill and Ted's future selves' lives were, we never see a point where they separate - they may be divorced and miserable and living in the van or in prison, but they've always got each other.
• The "couple of couples" therapy scene has its awkwardness (particularly when Elizabeth and Joanna explain why they wanted to go to therapy), but there's also how despite their own frustrations about their music, Bill and Ted are genuinely happy on the domestic side of things. Each just can't stop praising his own wife, his best friend, or his best friend's wife. When Elizabeth and Joanna say they're unhappy seeing them constantly stressing about achieving their destiny, Bill and Ted just want their wives to have the kind of lives that literal princesses deserve.