Brox's Kiss, the hot pink short sword in With Strings Attached, causes people of the opposite sex of the wielder to fall in love with and obey the wielder. Works perfectly — until the wielder loses control of the sword for more than a few minutes. Wisely, she runs off.
In the appropriate named Bleachslash fanfic Love Potion is all about type two attempted by Ichigo at Urahara's suggestion, which predictably goes wrong as the target doesn't eat the cookies...but everyone else does.
According to Equestria: A History Revealed, this was used by Discord en masse to cause the downfall of the Equinus Republic, cumulating in a giant orgy from the ponies in parliament. It is meant to be taken as Squick and with as much questionable validity as it sounds.
In Run Ichigo Run, Nemu is tasked by Mayuri to drug Ishida as revenge for attacking him and stalling an experiment, but a mistake results in Ichigo it getting hit instead. Since the drug was calibrated for Ishida, it has a different effect on Ichigo: every female he encounters falls in love with him, including lesbians and even his own sisters. Even Nemu is affected, despite the fact that she knows what's happening. As the title suggests, Ichigo spends most of the fic running to preserve his chastity while trying to find a way to remove the drug's effects.
Arthur suspects Merlin of using a love spell on him after he finds out about Merlin being a wizard.
Rosario Vampire: Brightest Darkness Act IV: Chapter 17 reveals that Ruby kept the original sample of Yukari's love-struck potion for some reason. Falla, Apoch, and Astreal mistake it for perfume and use it, and Hilarity Ensues when Moka, Luna, Yukari, and Kokoa end up dosed with it as well.
Harry Potter and the Methods of Rationality: Discussed by Professor Quirrell in regards to witches using them to enchant and rape Muggle men (some wizards also do the same thing to Muggle women). It also alludes to how Voldemort was conceived, something few know about. Quirrell has been possessed by him, however...
Domoverse: An unintentional one, with repeated applications of Glitch's happiness spray.
Love Potion Madness is a The Loud House fic that involves Lana using such a potion intended for Lori and falling in love with Clyde, thus teaching the latter about age gaps.
In this crossover fanvid between Cinderella and Sinbad: Legend of the Seven Seas, Marina is in love with her friend Cinderella's husband. In her jealousy she pays someone to change reality so that Prince Charming loves her, not Cinderella. It's only a temporary change that quickly wears out. When Charming wakes up to Marina in his bed, he has her arrested and imprisoned.
Regaining Perpsective centers on Cupid (appropriately enough) getting a type 1 and 3 love potion which she uses on Oliver. However, she's cautioned that if he encounters someone he genuinely loves, the drug will amplify and focus those feelings, and override the focus on whoever he sees first. The plot is set in motion by him being drugged and then encountering Laurel. The fact that he did in fact see Cupid first is a plot point.
Interestingly, the morality of it is fully explored. Laurel stops things the moment she realizes he's been drugged, but is still ashamed and feels like she "took advantage". Oliver himself (once it wears off) and Roy express concern if he hurt her under the effects. Also a funny moment when Roy's glad Oliver didn't see him first:
Roy: Well I dodged that bullet. No offense.
Oliver: None taken.
Felicity: Oh, that wouldve been funny. Assuming, you know, everything turned out fine.
Luckily for Terra, however, the harmony-goddess Cosmos hears Terra's prayer for forgiveness and realizes that Sephiroth has trapped Terra between a rock and a hard place and pulls a literal example of a Deus ex Machina, revealing the nature of the evil influence under which Terra had fallen when Firion found her in a compromising position, and for this reason Terra isn't held accountable for her under-the-influence actions.