Since no one mentioned them so far I might as well show some love to the best German band ever Scorpions which is one of my favorite rock bands. Others are Queen, Eagles, AC/DC, Guns and Roses, Led Zeppelin, Foreigner, Toto, Bon Jovie, Pat Benatar, Thin Lizzy and pretty much all other rock/metal bands/acts that had huge hits in the 80s and before that.

It just Eagles and not "The Eagles".

Fleetwood Mac and Stevie Nicks. Especially Stevie Nicks. There's nobody to have ever been on her level. Florence + the Machine got close but no cake...

Avenged Sevenfold for me. I'm glad someone else agrees in this thread!

I think both Pat Benatar and Tina Turner are close to being on the same level and at one point both where more popular/famous as solo artists then Stevie Nicks.  But overall I would give the edge to Stevie Nicks also since she also wrote some of her own material while Benatar and Turner only covered songs that where written by someone else.

Benatar and Turner have good voices, yes, but there's no way that they can compete with Stevie's pure talent. She actually wrote a vast majority of her own material, the kind of songs others wish they could write :)

That is true but in the past there just weren't that many female song writers and most female singers covered stuff that was written for them instead of using their own material. 

The real greatest German band ever: Helloween!

Metallica.

I love most forms of rock music and rock music as a whole is by far my musical preference, but even though Metallica is my favorite band, they aren't in my favorite sub-genre. I'm leaning more towards the more classic rock. I'm living a few decades too late when music is concerned. Metallica though is to me the most well-rounded, which is why I like them the best even though they don't have the best individuals.

Other favorites of mine include;

Queen
The Eagles
Led Zeppelin
Ozzy Osbourne and Black Sabbath
Nirvana
Muse
Linkin Park
Dire Straits
Boston

And loads from the '70s and '80s.

I'm surprised nobody has mentioned Rush yet.