Don't buy your dad a gift card for Father's day, his birthday, Christmas, or any other occasion in your life. The days of gift cards should be over, but alas they seem to persist.
If you are looking for 1 proven way to impress your dad, give him an experience. The experience should involve your time, that way you can make memories together. On Father's day, find something you can do together, even if you lack common interests.
Dad's aren't celebrated enough anymore. All too often they are cast as the aloof, disinterested part of a family in commercials, movies, and sitcoms. Sure, dads have their moments, but the comedic destruction of dads is overplayed for me. Take a moment and watch TV commercials about dads. All too often the marketers are using gimmicks to play the dad as something less than he is.
You can connect with your dad. You don't need gift cards to do that. Talk to him about his life, his experiences. That in itself is a fantastic gift. If you want to give him something, make it personal and relevant to him.