Shatner has gotten about 50 years of Fame Millage from that one role on Star Trek, but it turned out to be a very influential show. Nobody could have predicted it at the time. I’m generally not a Sci-Fi fan, so I never made time to watch it. Of course I’d heard about it.
Shatner has had a ball being Shatner.
Shatner was a comic hero as Denny Crane on Boston Legal too, my favorite episodes focused on his character.