The Donna Summer and Mel & Kim tunes were great, as above, and I have a soft spot for Bananarama's 'Love in the First Degree'
I suppose we're obliged to mention Roadblock, the tune that people couldn't believe was by SAW because it was so 'credible', but I was never very fond of it myself. Far preferred Bananarama.
Edit: Beaten to the punch by one minute! Damn my substandard typing skills.