Sometimes the best gift is not a thing at all but an experience. Concert tickets. A subscription to something he will actually watch. An activity or a meal out. These gifts work because they create a break in routine rather than adding more stuff to manage. An adult son will appreciate something that gives him something to look forward to or a shared experience with friends. The value is in the time and the enjoyment rather than the object itself. These are the gifts that matter because of what they allow him to do rather than what they are.