...3) Jim Rockford (The Rockford Files)
1) Thomas Magnum (Magnum P.I.)
MAGNUM? It all comes down to Thomas friggin' Magnum?
Yeah, that's what I thought. But what were you expecting? This is TELEVISION!!!!
It's just a popularity contest, fer cryin' out loud, and an amiably hinky one, at that.
Voting was done via the internet only (so right off, say goodbye to entire segments of "America"). Absolutely anyone with a few minutes and a mouse could vote -- regardless of their knowledge or background.
The producers were further curtailed by what they could -- and couldn't -- get the rights for, so even the short-list that people were asked to vote on was less than all-encompassing.
So what we were left with was not the best or even necessarilty the most popular of all TV and film detectives, but the most popular among a short, pre-selected list of TV and film detectives, as voted upon by a relatively small segment of the population that possessed both internet access and the knowledge and inclination to use it (ie: middle-aged and younger, generally), which would also likely skewer the results to those shows in more recent memory. Which may in turn explain why we have one movie from 1941, one movie series from the thirties and forties, one TV show from the fifties, one (arguably)from the sixties, and everything else from the seventies onward.
...MAGNUM? Yikes. I mean, I know it was popular, but THAT popular? The critic in me just can't let it go. Everytime I caught an episode it seemed to be one of the Higgins nagging/Thomas whining-and-smirking episodes. The most sustained gay fantasy ever on American television. Why do you think none of those women lasted?
Given that this was essentially a name-recognition/popularity contest, I'm impressed that Rockford placed as well as he did.
Magnum, P.I. struck me as a mix of serious and humorous that didn't quite work, but it was the kind of show that could be enjoyed casually. Good-looking protag, exotic locale, car chases, shootouts, rockin' theme music.
Incidentally, in the original pilot script, Magnum was a more classical James Bond-type with a girl on each arm. Tom Selleck wanted to play someone quirkier, less perfect, and Don Bellisario agreed. IMO, Bellisario's current show, NCIS, is a more successful blend of serious and quirky.