Based on the frequency of my repeated listenings I have chosen to provide links to three beautiful Ilayaraja compositions, which IMHO rank among the finest of his output.
1. Keeravani from Paadum Paravaigal -- A beautiful composition in the Keeravani scale -- wonderful mix of guitar and violin -- what an amazing start --- plus SPB singing in a fine bass voice. (SPB's amazing sense of Thalam is very evident here -- look how Janaki struggles in the last lines of the charanam "kanavugal pala valarthen...")
http://merlin.cs.uic.edu/download/tamil-film/Keeravani.mp32. Dheem Dheeranana from Enakkul Oruvan - A beautiful "thillana-like" dance composition in the Suddha Dhanyasi Ragam -- again some fine orchestration here -- wish the people who do orchestration for carnatic songs take a lesson or two from Ilayaraja!
http://merlin.cs.uic.edu/download/tamil-film/Dheem-Dhiranana.mp33. Madura Marikozhundhu -- from Enga Ooru Paatukaaran - in Mayamayava Gowla scale -- note that similar to the compositions above, there is splendid western orchestration -- but then the song itself has a very "folk" flavor -- a beautiful mix of some fine poetry and chorus singing! Listen to the charam lines ("pottunna..") -- each long line spans two beat cycles and set to a beautiful pace -- tops the list!
http://merlin.cs.uic.edu/download/tamil-film/Madhura.mp3Enjoy,
--venkat