Pro photographer Thomas Hawk gives good advice in his article about getting attention on Flickr (whether that's a good thing or not is a different matter!) that you should upload fewer shots with the best one last.
So if you're an Aperture user, how do you accomplish this sort of forced upload order to Flickr without having to upload each photo individually? I'm using the Connected Flow FlickrExporter plugin for Aperture, and all you have to do is choose your photos in reverse order with the best one selected last.
Here's How to Force Upload Order in Aperture
Let's say you have 5 photos to upload, since 5 is the number that Flickr will announce to your contacts if they have chosen to be updated via email. Choose the couple you judge to be the worst first, and then choose the top ranking ones in reverse order best-is-last, holding the cmd key down while you click. Remember the keyboard shortcuts that are similar in both Windows and Mac: click to select, Shift-click to select a range, Cmd (or Ctrl)-click to select noncontiguous items.
When you do File, Export, you will notice that they are in the selected order.