What is the best gift you can give your dad on his B'day?

My dad's birthday is very near too. Actually, just a week from now. And just like you, I'm also confuse of what to give him. I remembered the first time i had my salary, he joke about wanting "briefs" which was given to him ofcourse. We talked about it and he said he was just kidding. Yeah! He would rather have cash instead he said. So he can purchase his own wants.