Oh boy -- that's kinda tough. When I was a kid, Superboy was on an animated series -- but there was no sign of a Supergirl outside of comics. I was shocked when a classmate informed me of her existence.

Then in the 80s we had a Supergirl film that was mostly missed by an audience, and a so so Superboy series in syndication that lasted several years. So from 60 through 90s -- I'd say Superboy was more iconic.

With the Supergirl TV series -- and Superboy largely absent from screen -- and comics -- I'd say Supergirl has definitely pulled in front.

I'd like to see a classic (young Kal-El) version of the character be used with the Legion -- if they ever return.