What do you think about me saying that there is nothing that I want from my parents in their will?
What about your parents makes you say that?
They are so stingy with their money so I won't get anything anyway.
It's okay to be honest with them. Be sure you mean it though. I've heard stories of people getting nothing 10 years later because that's what they told their parents to do.
I just want them to bleed. I'm glad they are dead so I can enjoy the feeling I have now.
Letting your parents know how you sincerely feel is best. However, you should consider what it is you would truly like from them. Think about it logically, instead of considering it out of a hurt place.