S.B.
Try doing something fun with him that he would love & is not something you would normally do. For example, for my husband's bday we are going to go & get archery lessons. For my last bday we went out and got sport clay shooting lessons. (These are things we've both wanted to do, but for some reason never did before.)
Other ideas: a charter fishing trip (if you live near the shore), skiing trip, a hike in the woods (if the weather's nice), rock climbing at an indoor rock gym. I think there is a place in PA where you can get race car driving lessons. Its one day & its expensive, but at the end of the day the guy would get to drive a race car around the track.
Good luck.