One of the most memorable first kisses in movie history belongs to Hermione Granger and Ron Weasley of the Harry Potter series. After seven books and eight long movies, these friends finally cement their relationship into something more. However, while the iconic moment in Harry Potter and the Deathly Hallows Part 2 is dramatic and satisfying, it doesn't culminate the years of tension and feelings in the same way that the book version does.
One of the main reasons the moment doesn't land the same is that director David Yates decided to leave out a crucial side story that begins during Harry Potter and the Goblet of Fire and is further developed during Order of the Phoenix. Without this storyline, the book version of the kiss isn't possible, which forced Yates to create a new situation that gave the couple their long-awaited moment.
Back in J.K. Rowling's Harry Potter and the Goblet of Fire, Hermione starts an organization called the Society for the Promotion of Elfish Welfare (S.P.E.W.) in order to champion the rights of house-elves everywhere. She learns that Hogwarts employs house-elves in their kitchens and that their treatment of them was less than standard. Upset and enraged, she starts this organization and keeps it going until the end of her time at Hogwarts. Ron and Harry were the first to join S.P.E.W., and it grew from there.
During the Battle of Hogwarts in the final book, as Harry, Ron and Hermione are scrambling amidst the chaos, Ron remembers that the house-elves will likely be trapped in the kitchens and probably need help. For Hermione, this was a milestone moment in her relationship with Ron. His genuine care and maturity at that moment completely overwhelmed her, and their long-anticipated moment finally arrives when she kisses him.
In the movie version, the moment comes when Ron and Hermione are down in the Chamber of Secrets destroying one of the Horcruxes. After the backlash of destroying the Horcrux, and in the heat of the moment of the battle and everything else going on, the couple finally kiss. But while it's dramatic and really fits the moment, it doesn't do their relationship justice.
After all that Hermione and Ron had been through, it was ultimately their difference in maturity and responsibility that caused hesitation on both of their parts. Even though at the end of Half-Blood Prince they both knew each other's feelings, they still didn't act on it. In the books, Hermione needed Ron's act of selflessness at that moment to convince her that he was ready for her, while the movie treats it more as a matter of time rather than a cause of course and action.
Sure, both versions of Hermione and Ron's first kiss were long-awaited and well-done, but the book version did more justice to the characters and their journey together, from friends to partners.