Who are the most overrated musical artists?

RADIOHEAD

And Eminem. He wasn’t witty or smart, just remarkably self-centered, and strangely able to express that.

Saliva, Godsmack, Stereophonic, Mudvayne, Limp Bizkit, et. al Rage against the machine and Korn pioneered rap-metal. Theirs is good; yours is not.
NOTE TO BANDS: MISSPELLING YOUR NAME DOES NOT MAKE YOU COOL.

OK, well gotta agree with a few of these.
Add absolutely any of the girl/boy bands over the years, especially the current crop of manufactured ones.
Elvis - but only the context of today, he was probably exciting at the time, but just doesn’t stack against his contemporaries (Buddy Holly et al).

Add anybody who thinks that good lyric writing consists solely in being obtuse - this just ain’t so.

OK I love a lot of punk rock, especially the earlier stuff (Ramones, Televison etc). This is bound to flavour my interests - it makes a lot of other musical styles look lacking in energy. Then again I also love Nick Cave.

Further to the above I gotta say that a lot of what passes for music is passionless. Technical genius on its own does not make for great music - it requires passion. That is what makes Mario Lanza better than Luciano Pavarotti, not the ability to hit the exact note, which pavarotti can, arguably do better, but the intense passion that lanza brought to his music.