Polyjuice Potion
The Polyjuice Potion allows the drinker to appear to be another person for a set time, most commonly an hour. It is made with several ingredients, including a part of the person that the drinker wishes to turn into, such as a strand of hair. Its taste and appearance seem to depend on the person. It is first used in Chamber of Secrets to allow Harry and Ron to transform into Crabbe and Goyle so they could question Draco. In Goblet of Fire, Barty Crouch Jr uses it to disguise himself as Moody. In Half-Blood Prince, Crabbe and Goyle use the potion to disguise themselves as young girls while guarding the Room of Requirement. In Deathly Hallows, it is first used to transform members of the Order into Harry look-a-likes, creating decoys from Voldemort and the Death Eaters. Later, Harry first uses it to disguise himself at Bill and Fleur's wedding as a fictional "Barny Weasley". Also, Harry, Ron and Hermione use it it infiltrate the Ministry of Magic, by disguising themselves as Ministry workers. Later he and Hermione disguise themselves as a middle-aged Muggle couple while exploring Godric's Hollow, and finally Hermione disguises herself as Bellatrix in order to break into her vault at Gringotts. The potion only works correctly with human-to-human transfiguration, as Hermione discovers in Chamber of Secrets when she inadvertently takes a dose containing cat hair.
I think Veritaserum is more powerful but Amortentia is much much more powerful
Veritaserum
Veritaserum is also known as the truth potion or truth serum. Only three drops of this potion is needed to force anyone to tell the true answer to any question. An example of its use is when it is used on Barty Crouch Jr. in Goblet of Fire. When Dumbledore asked him how he escaped from Azkaban, he told him truthfully that his mother rescued him from jail. In Order of the Phoenix, Dolores Umbridge tried to use it while interrogating students about their affiliation with Dumbledore's Army, but was actually using an ineffective potion supplied by Snape, and Harry pretended to drink it. In Half-Blood Prince, Harry considered using the potion to get Slughorn to reveal his memories about Voldemort, but thought better of it, and in Deathly Hallows Rita used the potion to extract the story of Dumbledore's childhood from Bathilda Bagshot. Rowling has revealed on her fansite that Veritaserum can be fooled using Occlumency and is not usually accepted in wizard courts.