The Hugo and Nebula wins are the ones publishers like to splash across the winners' covers, too. I think they do "count" disproportionately in the minds of the fans (as opposed to casual readers of the genres) partly because they're used to seeing them on those book covers.

I remember one set of Nebs, many years ago now, where Kim Stanley Robinson was the only male winner. The male SF writers on the old Genie SFRT flipped out about it. Some came right out and accused women of voting only on the basis of gender or badgering people to vote for various women. They refused to believe that those stories and novels were considered the best.