THE MOST UNDERESTIMATED & THE MOST OVER-RATED BANDS

You just listed 9 of my favourite bands in two lists (I never got Jethro Tull) not sure what that means apart from you liked the 60's and 70's, not so keen on the 80's and 90's.

The most over rated;

Nickleback.
Creed
Panic at the Disco
Amy Winehouse
Any and every top 40 hip hop "artist" including but not limited too; Kanye West, P Diddy, Timbaland, and 50 Cent.

The most underrated ;

Ben Harper and the Innocent Criminals. 
Robert Randolph and the Family band.
Tom Waits
Neco Case
Flogging Molly

The UNDER-RATED list, is about really great bands, who wrote several hits, but in a list of let's say the 10 greatest bands, you will often not find them.
It's a personal opinion I posted, so I do see already nice answers. Feel free to judge, share and giving critics, better what would be YOUR list.

Doc...Radiohead?????? I'd say they should be on the Underrated list...Original, great songs and an "I don't give a shit what you think attitude" what more do you look for in a band?

AWESOME: Why classic rock bands? Because they are CLASSICS. I'm an old fart °1955 AND from Europe. Like just above me AN EUROPEAN, so I might be sticking in the 60-ties/70-ties. Although I was MD on one of the greatest rock festivals. And as posted by TIBERNIUS: there are some groups that I under-estimated, some bands can "fit" really well in over-estimated bands or performers. I really worked hard on this topic, at least 1 hour for a topic that can be answered in a few minutes. I will add some more info.
The more I read it, the difficult it gets. WE ARE ALL "VENTILATING" our opinion
I GIVE YOU SOME MORE:
OVER-RATED
1) MICHAEL JACKSON. WHAT DID HE PROVE except for his "copied" moonwalk, see J.L. HOOKER
2) HAPPY MONDAYS
3) STONE ROSES
4) PRINCE
5) SPRITNEY BEARS. BRITNEY SPEARS (bypass terrine = anagram)

UNDER-RATED
1) NICK CAVE AND THE BAD SEEDS
2) QUEEN
3) BEE GEES (if you see how many beautiful songs they composed.) = it was "not-done to be a fan of the BEE GEES
4) LYNARD SKYNARD
5) MARVIN GAYE
2)
-
Now HALF CHORDIE WILL BE ATTACKING OR EVEN NUKE ME
- Jimi HENDRIX: what did he prove? FANTASTIC GUITAR PLAYER, OVER-SKILLED, but what did he contribute.
- THE

I agree with some of the others here

Over-Rated

- U2 - Never got ‘em, never will

- Guns-N-Roses, Bon Jovi, Poison – there’s a slew of these bubble gum pop rock bands that were way to popular – Either you’re metal or your not, and these guys were NOT

- Rod Stewart – Has any singer ever had so much success with a smaller vocal range?

Under-Rated

- The Who definitely belong here. IMO they were / are more talented than the Stones in every aspect, but never reached the level of success the stones did.

- The Kinks - I also agree here. A large part of their problem I believe was due to a battle with the US musicians union in the 60’s that banned them from touring here at the height of the “British Invasion†. No telling how huge they would have been without that issue.

- Aerosmith – These guys have staying power that few bands have ever achieved. And even while pushing 60 years of age they are still producing good music and touring hard. I saw them just a year or 2 ago (for about the 6th time) and was still blown away by the sound as well as the energy they give in their show. They belong in the "elite" of American Rock Bands

CORRECTION.
IT'S NOT BECAUSE A BAND OR A PERFORMER IS LISTED AS OVER-RATED or UNDER-RATED, THAT I DON'T LIKE THE BAND. Like Jimi Hendrix, I love that guy AND he is A MODEL-EXAMPLE how thin the line is between A MUSICIAN and A SUPER HERO.
JIMI HENDRIX is considered one of the greatest and most influential guitarists in rock music history. He learned by practising almost constantly, watching others play, through tips from more experienced players and listening to records. One of his first bands were THE VELVETONES, and I believe his first electric guitar was a SILVERTONE DANELECTRO.After his military career he played in a band The King Kasuals", playing mainly in low-paying gigs. He won a first price and earned a spot as the new guitarist for the Isley Brothers' band. Later he was also hired by little Richard and in 1965 CURTIS KNIGHT, but in fact it all started in 1966, in London, thanks to CHAS CHANDLER and after successful gigs the word of Hendrix spread through the London music community. His showmanship and virtuosity made instant fans of reigning guitar heroes Eric Clapton and Jeff Beck, as well as members of The Beatles and The Who, whose managers signed Hendrix to their new record label, Track Records.
THIS IS WHY I WROTE ABOUT THE THIN LINE BETWEEN A VERY GOOD GUITAR PLAYER and a GUITAR HERO. And yes, I placed him maybe in the wrong list, and I WOULD Love to see him playing in stead of seeing him dying. VICTIM OF HIS SUCCESS? More than PROBABLY.

Carlos Santana is probably the most under-rated guitarist on the planet. If you ever read the ridiculous "50-best" or "100-best" lists he is never in the top 10, 20, or even top 30. You will see clowns like Slash on those lists, or similar clown-losers.

Also, the Allman Brothers Band is vastly underrated. They improvise like no one else, along with Carlos Santana.

I looked again, and there are as much opinions as there are people.
More than once you find an artist, let' say SANTANA, in 2 categories.
- good guitar player
- bad guitar player.
I THINK IT IS IMPOSSIBLE TO BE OBJECTIVE.
A test which should be nice, let people 70-80 years old listen to a dozen musicians, and ask them after the test, who they hated most, and than you reverse the results    

I can't imagine the results of that test... "Which one was he again?"