True Love's Kiss is a TV Trope term and is basically a form of The Power of Love. It refers to the love interest or character in love being cured by the kiss of true love. True Love's Kiss can cure any curse, spell or hex and can even revive the dead. True Love's Kiss is commonly used in fairy tales.
Sailor Moon: In the first managa story, Mamorou brings Usagi back to life by kissing her.
Howl's Moving Castle: After Turnip saves everyone by using his pole to slow down the last bit of castle floor, Sophie breaks his curse by kissing him as thanks, restoring him to his true form as a prince. However, Sophie was in love with Howl so she didn't return his feelings. The Prince does leave though to end the war.
Sonic the Hedgehog: In the 50th issue in the comics, Sonic awakens Sally Acorn from a coma with a kiss. Also in the 2006 game, Princess Elise kisses Sonic. Her kiss along with the Chaos Emeralds, brings him back from the dead and turns him into Super Sonic.
Inuyasha the Movie 2: The Castle Beyond the Looking Glass: As stated before in The Power of Love, Kagome is able to bring Inuyasha back to half-demon status by declaring her love for him and then kisses him.
Snow White and the Seven Dwarfs: The Victim of the Sleeping Death can be revived only by Love's First Kiss when The Prince kisses Snow White in her Glass Coffin to awaken her.
Sleeping Beauty: After Maleficent cursed Aurora to die at 16 by pricking her finger on the spindle of a spinning wheel, Merryweather changes it to sleep until she receives Love's First Kiss with Prince Phillip.
The Little Mermaid: Technically it doesn't get to be used, but Ursula told Ariel the spell she put on the young princess would be permanent if she receives a kiss of true love with Eric.
The Matrix: Trinity revives Neo with a kiss after he is killed by Agent Smith.
Shrek: Fiona is cursed that every night she turns into an ogre, until she revieves true loves kiss, where she would become a princess permanately. However, do to the fact that she falls in love with, and kisses Shrek, she becomes an ogre permanately, and is happy with it.
Yu Yu Hakusho: Keiko revives Yusuke with a kiss after Yusuke was killed in a car accident and Keiko saved his body from the burning house.