Buy shares in Daimler, Tesla and BMW (I'd avoid American car companies unless he likes Ford or GM; avoid VW because of their emission issues), Lego, Manchester United or other football club (or their sponsors), entertainment companies (Disney etc), building and civil engineering construction companies, shipping companies. Wonder if you could buy shares in entire industries rather than individual ones.
You could always buy the Wall Street Journal or Financial Times, go to the share index page and explain to him the different companies that are listed and which industries they are in. Ask him to choose 10 companies he likes - if too difficult, use darts.
Best of fun!