So the solution is pretty simple:
1. As administrator, go to the Organization and then Utilities. Click on the Workflow Template Administration. Check out the workflow and Edit.
2. Click on the specific task so that the window appears with all the task tabs (general, activity, participants, etc.)
3. Click on the "routing" tab.
4. The column on the left displays all the different routes available once the task is completed.
5. Move the routes up and/or down so that the "default" route is the very first option listed.
6. Click OK and then check in the workflow template.
That's it...now when you complete the task the default route with be listed first.