3. Donna Noble (2006, 2008)
Donna Noble (played by Catherine Tate) is a unique entry into the realm of NuWho companions. Namely, she's the only one that hasn't at some point been in love with the Doctor. I mean come on, with Rose it was a new idea, but with
every single one of the successive companions? Give us a break. Which they did, in the form of Donna. While sometimes abrasive and even annoying, she usually shone nonetheless in each episode. She had witty banter with the Doctor, served as a good audience surrogate at times, and above all, was useful! Well, not all the time. But occasionally. Unfortunately, almost immediately after her departure it went back to the same old routine. Here's Amy, she loves the Doctor, blah blah blah (though they got that out of the way quick enough and made Amy into a pretty decent companion, thank goodness). But for one short series and a special, we had a truly unique NuWho companion.