Stevie Wonder and Todd Rundgren. And I don't even do that kind of music today. Anyway, basically I like songwriters that could take a simple structure and twist it so it's refreshing again. Stevie Wonder is an excellent example as he uses jazz chords, even half-step scale changes for pop tunes. Todd is famous for his cluster chord structuring around pop songs even if he admits he got inspired by Laura Nyro for that.
It just shows that if you are creative you could turn a typical pop song so something really special. Another good example actually are all the XTC pop songs over the time. Pop but with a cool twist.