Hmmm, a few to start off with:
Sidriss: Papa Don't Preach (Madonna)
Gretel, Hordriss: You're So Vain (Carly Simon)
Lord Fear, Moggamoos: Everybody Wants To Rule The World (Tears For Fears)
All dungeoneers when questioned by Treguard before the Quest: I Will Survive (Gloria Gaynor)
Most dungeoneers half an hour later: Tragedy (Bee Gees).
Several teams throughout their Quest: I'm Still Standing (Elton John), Livin' On A Prayer (Bon Jovi).
Series 3 Team 10 after their weird attempt to offer the goblins a present: Why (Annie Lennox- yay)
The life force quiche: That Don't Impress Me Much (Shania Twain)
Morghanna, Mildread, Malice, Aesandre, Lillith etc.: I'm A B
itch (Meredith Brooks)
Mr. Grimwold: I Eat Cannibals (Toto Coelo)
Oh, and of course, Mrs. G. is summed up by so many songs- The Best (Tina Turner), You Sexy Thing (Hot Chocolate), Every Little Thing She Does Is Magic (The Police), Nothing Compares To U (Sinead O'Connor) etc. etc. etc.
"Sometimes of the Grey, but always of the Green, dearie. Shurrup Brollachan! Have you seen Festus, my dear? I need to take him back to Cornwall. " [cackle]