Well?
I say Kondo. Tanaka’s greatest are better than Kondo’s, but Kondo puts out more consistant hits (and continues to do so. Delfino Plaza is as catchy as any of his other classics).
Never heard of Hip Tanaka, but I have heard of Kojo Kondo. Now that I know who Tanaka is (I checked), I say Kondo, for the same reasons you did- although Tanaka has written some good music, Kondo is more proficient. Doo-doo-doo-doo-doo-doo!
Another vote for Kondo. Tanaka’s work, while good is fairly forgettable - as evidenced by the fact that I can’t conjur up a single bit of his music even knowing what he’s done.
Although Kondo has more of a resume, Tanaka did work on the soundtrack to Earthbound and so he gets huge bonus points for that, as well as for Metroid. I can’t discount all those Mario and Zelda themes Kondo has done though, so I’ll have to go with him.