I'm going to decide not to give a speech at graduation despite my parent's wishes
What type of speech did your parents want you to give?
I was going to expose some particular students or teachers as an asshole.
Interesting that your parents wanted you to give that kind of speech. Regardless, the decision to give it or not is up to you.
They said to do it or not whatever i want. Plus, I've got drama going on with these students.
I'm proud of you for not going through their wishes. Even though they are your parents, you still have your own morality code to live by. The teachers and students would be happy to not have their special day ruined.