Theater tickets, magazine subscriptions, a literary best seller, a bottle of fine wine, adult puzzles, a chess set if he plays....a personally made/knitted item such as a scarf, hat or sweater.....a framed photo of something meaningful, a movie video, a music video, movie tickets, concert tickets, favorite sports event tickets, golf stuff if he's a fan, wine stuff for same. A gift card to his favorite restaurant or a box of edible goodies such as dessert assortment.
You know the recipient better than anyone so you just have to think out of the proverbial box. Some close friends of ours once sent us a case of frozen steaks/veal cutlets/seafood etc., as a 'thank you' for allowing them to stay with us (over a week) after they sold their house and moved to another part of the country.