The old version of Prema Yatralaku song from Gundamma Katha (Telugu):
Maestro's version from Detective Narada. This forerunner to current day remixes is very innovative and creative in the sense he has added another layer of melody to the existing song with new interludes.
Then sindudhe vanam (music: GK Venkatesh, with Raja as assistant). Maestro has spoken a lot about this song in his recent concert.
Dr Rajkumar's debut song from Sampathige Savaal (music: GK Venkatesh, with Raja as assistant). Refer to my Post # 13 here:
(I got some of these songs from CoolToad, thanks to them!)