Here's a look at the five most popular Tamil film songs of 2011.

Why This Kolaveri Di?

Trade analysts are still scratching their heads over just what made this, out of so many other similar numbers, popular. But fans are very vocal in their adulation: it's a combination of Dhanush's voice, his antics during the filming of the song, and the simple English-Tamil lyrics.

Debutant composer Anirudh Ravichander turned up a whopper of a song for Aishwarya Dhanush's 3 and the song went viral within days, collecting more than 25 million hits on YouTube. Clearly, this is the numero uno of the year, not only in India but in many parts of the world too.

Harris Jeyaraj has always been known for his melodious compositions. His best this year was for Engeyum Kaadhal and Ko. But Ennamo Edho from Ko was particularly popular, sung as it was by Aalaap Raju.

What made it even more special was lyricist Madhan Karky's beautiful Tamil, which was evident in words like 'kuviyamilla' and attracted some well-deserved attention.

This seems to be the year of Dhanush, both as actor and singer. This one, too, was sung by him, as brother and director Selvaraghavan provided the lyrics.

Mayakkam Enna, which was all about love, had songs by G V Prakash Kumar and this one, lamenting the perennial ill luck of the protagonist when it came to work, love and life, hit all the right notes.

The signature song for Ajith's Mankatha, tuned by Yuvan Shankar Raja, made sure we sat up and noticed, with its snazzy music, lyrics, and the way it showcased Ajith as a criminal mastermind.

This rousing song took everyone by surprise even though singer and lyric-writer Simbhu predicted that it would be a chartbuster right away.

Composed by Yuvan Shankar Raja for the film Vaanam, the song had Simbhu shrieking about his love -- or otherwise -- for the girl of his dreams. And despite the criticism that the words were crude and harsh, it still went on to become a hit.