Do something small, like a small gesture that shows you love him.. Just like that commercial where the son wakes up his father takes him to the table to eat sum oreos n waits for 12:00 and says happy fathers day dad i bet that was one of the best fathers day gifts dat man got that day.. :)
make him a surprise party with everyone u think is special to your family,oh and it has to be the place he loves the most,with his favorite everything like,favorite flavored cake,favorite flavored ice cream,favorite color of balloons and a great cheer!!!(He will love it if he loves u)OR if u want gather everyone to give 1$ so u can buy him something he wants at his party!!!!
You because nothing's better than just being with your family regardless of their actions recently and currently.Also a little something that says you really do pay attention to him.Some kids don't have father's to give a present to or father's sometimes doesn't have a kid to get presents from,so i say that anything matters.
LOVE and telling him that! SHOW love. BE love. Noticing the small things about him and commenting on it. Then perhaps buy him something that he could really use vice something cute or what TV advertisements state that he should want. Remember it's not the material things that matter the most. It's showing LOVE. In the spirit of Ma'at...Peace, harmony, balance
give him something he would NEVER buy for himself, but he would like. Like a new recliner, Dr. Scholl's foot supporting shoe inserts / new socks, detailing for his vehicle or fix something that has been flawed or wrong with his house/car for the last couple of years.