Personally, as a dad, I really don’t know.

Getting a consumable in some way is a safe bet. I love Reese’s and coffee, if my kid got me a few Reese’s or some weird new coffee , that’d be awesome. If there’s a hobby, something he goes through a lot of would also be great.

I find if I need a tool or thing for a hobby or activity, good chance I already have it. If that’s ever not true for your dad, then its perfect. But I always need more materials for things. Coffee, 3d printing filament, art supplies if he does any kind of art, things like that. For barbecuing, exotic meats would be cool, like bison.

Beyond safer consumable things, the best gift is something that makes some workflow of his easier. My coffee routine, my commute, my favorite games, they all have a routine, and if you can make that routine easier, simpler, or more fun, that’s a win that he’ll use every time.