I'm going to get tattoos against my parents wishes.
Is there any special reason you'd like to get tattoo?
I'm tired of them telling me what to do.
You should make sure getting a tattoo is worth it. It's permanent, while resenting your parents will probably fade with time.  I'd strongly suggest weighing the short and long term effects of doing this.
Who cares? I'll get it done no matter what.
That's your prerogative.  That being said, I hope you don't end up regretting this later!  Spite is not really a good motivation for doing anything.