Is Kreacher the best character in the Harry Potter series?

No. I don't personally think that there is a best character in the book series (everyone has a different opinion about every character), but Kreacher isn't one by any imagination.

1. He was biased to Hermione based on her blood, even though she was nothing but nice to him the whole time.

2. He hurt Buckbeak to ensure that Harry wouldn't be able to discover that Sirius was safe at home. This action also helped to destroy the last remaining Black family male, ending the whole family lineage.

3. He joined forces with Bellatrix and other Death Eaters

4. He gave Harry maggots. Sirius gave Harry the best Christmas present ever. Kreacher's present is only compared the best if comparing them to the Dursley's presents.

5. Kreacher isn't supposed to ask for anything in return or he would have most likely faced punishment. However, he murmured about people in the house and also stole from Sirius. Hermione made him a quilt.

The only redeeming factor occurred when Harry, Ron, and Hermione heard his tale of Regulus' death and gave him the fake locket. He only became nice to them after that moment. He even fought in the Battle of Hogwarts.

Dobby, on the other hand, was raised with similar people who worshipped blood loyalty and had similar biases to Sirius' parents. He brought down his master, Lucius Malfoy, and also helped Harry through nearly every book since (not the third). Fourth: gave him Gillyweed and also told him what was taken from him, Fifth: told Harry about Room of Requirement, Sixth: was sent to spy on Draco, Seventh: sent by Dumbledore to save Harry, Ron, Hermione, Luna, Dean, Ollivander, and Griphook, stabbed to death after trying to "injure" Bellatrix by Bellatrix.

These are just comparing Dudley and Kreacher. It's your opinion, but I don't know how you came to it. Maybe with some insight, I might be convinced how you came to your opinion.

I'd like to argue that Dobby is much better, but I did love Kreacher during the end of the series.

no... he isnt the best character... every character in that book teaches us something... evn kreacher.. but no.. he cant b the best!! harry is the best!!