I started with this top 100 listing as a reference (it was just the first one I found where it was an actual 1-page list, not 100 pages to click through):
http://stereogum.com/495331/vh1-100-greatest-artists-of-all-time/list/
My top 3 overrated were:
1. Nirvana (#14??? They had one decent song)
2. Bob Dylan (The man never could sing at all)
3. Jimi Hendrix (He could do amazing things with a guitar, but one thing he couldn’t do with it was make good music.)
Dishonorable mention: Janis Joplin at 72. (At least 1000 places too high; just horrible.)
I assume Velvet Underground at 24 was just a joke to see if anyone was paying attention.
Wow! A lot of stinkers in the top 20