I'd start this list with Star Wars (1977), but it was Harrison Ford's break out role. It wasn't his film the way these were:
Air Force One (1997) featured his "GET OFF MY PLANE!" line, and it gave moviegoers a reminder and a little charge of the old Harrison Ford electricity. But with films such as Patriot Games (1992), I think he is really just playing himself playing a cinematic action hero (not to mention he was taking over the role from another actor). I've always felt the Jack Ryan films were beneath him. And I'm not overlooking Indiana Jones and the Last Crusade (1989).