One song where I thought Lata-bai's version scored over Rafi-saab's version is
Teri aankhon ke siwa duniya me rakkha kya hai...
Yeh uthe subah chale, yeh jhuke shaam dhale..
Mera jeena, mera marna inhi palkon ke tale...
I find lot more passion and pathos in Lata-bai's version here... Again, I think lyrics play a big part why Lata-bai probably scores here......
Yeh ho kahin inka saaya mere dil se jaata nahi...
Inke siwa ab to kuchh bhi nazar mujhko aata nahi... (Latabai's version)
Somehow leaves a deeper impression than
Inme mere aanewaley zamaane ki tasveer hai...
Chahat ke kaajal se likhee hui meri taqdeer hai... (Rafi saab's version)
Is it just me, or others also feel that the lyrics, musical arrangement abd situation of the song in the movie are the key reasons why one version of the song sounds better than the other... the singing if we notice gets largely influenced by the situation in which the song plays in the movie as the singer needs to present the correct emotion for the moment in his/her voice...