9. Meg White - The White Stripes
There's probably a good subset of people baffled at the idea of Meg White being an underrated musician. Compared to any other drummer from around her time, what she does tends to be serviceable at best for the White Stripes, with nothing more than a basic rhythm on nearly every song. While there are a lot of simplistic elements to her style, that's actually precisely why the White Stripes work so well.
From the very beginning of the Stripes career, most of the the power was coming from Jack White's amazing leads and songwriting technique. Though Meg could have just as easily played some complicated music around his song, the amount of restraint she has in her delivery sits somewhere between incompetence and utter genius depending on who you ask. Then again, you need to be doing something right if you can make something as easy as Seven Nation Army and make millions of people move to it.
That not only speaks to the power of Jack's songs, but also to the core mindset behind the White Stripes as a whole. This was not a band that was looking to wow you with how fast they could play at one time. This was the kind of band who was more interested in stripping things down and bringing rock and roll back to the garage where it belonged.