Which are your favorite A R Rahman songs?

I am a big fan of A R Rahman and like almost all songs composed by him. He is my favorite music director. I listen to 'Chaiyya Chaiyya' (from Dil Se) everyday. All songs from Roja, Bombay and Humse Hain Muquabla are simply masterpieces. And I think songs from Lagaan depict his genius.
Which songs composed by him do you like?

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