Hard to defend Gordon as a good shooter. If he were, he would be in the top 3 discussion, given his other skill sets and athleticism.
If I was forced to decide between Vonleh, Gordon and Randle, I choose Gordon. This is based on watching them each play several games in college, and imagining who "feels" to me like his game is going to work in the NBA. I don't feel that way with Vonleh or Randle. I remember watching Indiana game vs. Michigan State this season, watching Payne outplay Vonleh, and wondering why he (Payne) was not getting the attention by the fans. For Randle, he works extremely hard, but seems so limited in what he can do offensively, and for him to make those same back to the basket moves in the NBA? The only guy who seems to have that game anymore and get away with it is Al Jefferson. Randle does not strike me as being on that level, or that long.
Worth noting: Michael Jordan and Magic Johnson, pretty good players in their day, were not very good outside shooters when they came into the NBA. They each improved, especially from 3 point range, over the years, through hard work and dedication. So I reject Nick's assumption that players don't improve their shooting percentage that much. Or, for that matter, that having a below average outside shot relegates a player to bench role status. That just does not square with the facts.