"But Daniel purposed in his heart that he would not defile himself with the portion of the king's meat, nor with the wine which he drank: therefore he requested of the prince of the eunuchs that he might not defile himself" - Daniel 1:8 (Audio)
The following sermons are on Daniel 1:8:
The Dangers of Digital Babylon, by Dr. David P. Murray (Video)
Daniel's Integrity, by Dr. Joel Beeke (Video)
When it is Right to Say No! by Rev. Colin Mercer