Before last year, I would have said James Blake or Max Miryni would be the prime candidates -- but both won their first tournaments. Even Vince Spadea broke through for the first time, with his recent win in Scottsdale (at age 29!).
But I've always maintained that the criticism of Anna K is horribly unfair. The point is, nobody considered Blake, Miryni or Spadea underachievers or "losers" the way they do w/ Anna K. I'm not blind to the fact that many people resent her endorsement income, as if it somehow needs to be "justified" w/ tournament wins.
C'mon, just to play at the highest levels of the professional game is achievement enough. Think of the high regard you hold for your club pro who, perhaps, got into the second round at Wimbledon one year, or once took a set off of Jimmy Connors.