Ranking Main Themes

[SSB_Fan]

My personal list
Snake Eater > The Best is Yet to Come > Theme of Love > Sins of the Father > Calling to the Night > Can't Say Goodbye to Yesterday > Heaven's Divide

Way to Fall and Don't Be Afraid also get special mentions from me, but those aren't main themes. MGS3 had some great music in general.

 

[Four-]

Best is Yet to Come > all.

And I agree, Way to Fall is incredible in its own right.

 

[Shaymin]

The Best is Yet to Come
Calling to the Night
Snake Eater
Theme of Love
Heaven's Divide
Sins of the Father
Can't Say Goodbye to Yesterday

 

[DanielMazahreh]

Easily "Best Is Yet to Come" from Metal Gear Solid on the PSOne.

Then comes Snake Eater, Calling to the Night, and Theme of Love.