Well, we’ve had a go at the 30’s and 50’s, so let’s see what has clogged your memory from the 1970’s.
First impression first, then add as many others as you think matter.
Cher.
Huh.
Mine was John Ritter, a la “Three’s Company”. Sort of weird.
I’ll go ahead and mention mine, since I doubt anybody else will name him: Bobby Fischer. 
Elton John. Not sure why
John Travolta
Richard Nixon
John Denver
+1
+2.
Regards,
Shodan
Jim Morrison. Even though he died in 1971, his was the first name that came into my mind.
Without reading the thread at all: John Travolta.
+1
Why? Because he was the biggest musical act of the decade, perhaps?
Elton John
ETA: And yes, that was without peeking. I don’t know why either, but that’s what popped right into my head. Of course I was a big fan of his in that era. Before I discovered real musical talent: KISS!
wow, I feel validated.
Funny that Carter doesn’t get a mention.
Venus Flytrap
Yeah, Wonder Woman was quite popular.
Another vote for Travolta
Yep, same here.
Led Zeppelin