Others questioned where David Bowie, Elton John and Bruce Springsteen were, though at least in my mind, those three are rock legends that maybe transcend—or at least don't seem right being boxed into—a category of "pop" artists.
Michael Jackson and Prince were certainly around prior to 1983 (and technically, George Michael's first U.K. Wham! single was out in fall of 1982), but to not include them would seem a downright crime, as they were completely inescapable that year and for many more to come.
Oh well, this ain't an exact science. Here then are the results:
1-2. Michael Jackson/George Michael (tied with 54 votes each)
3. Prince (33)
4. Robbie Williams (12)
5. Justin Timberlake (7)