Blender Magazine, a music rag from the folks at Maxim aimed at your boom-box-toting teenie, has published their list of the "50 Worst Artists Of All Time". You know that any such list is bound to step on some toes, but I think they may actually have committed a crime: the #2 artist on their list is Emerson, Lake & Palmer.
Caution: Truth In Advertising requires me to state that I own most of ELP's albums, either in vinyl or on CD. I've been to three live ELP concerts in my life, plus one for Emerson, Lake & Powell. I have piano music for three of their albums.
Having said that, I think I can factually dispute their inclusion on this list. The folks at Blender do not seem to be able to distinguish between "genres of music we just do not like" and "bad artists". Besides ELP, the list also includes Alan Parsons Project, Rick Wakeman & Yes, and Asia, all of which plied the heavily synthesized, classically-based rock music that ELP pioneered.
Playboy Magazine in the 1970s produced monthly lists of the current top 25 artists in terms of abilities in various categories. For many months, Keith Emerson was the #1 keyboardist, Carl Palmer was the #1 percussionist, and Greg Lake was consistently in the top 10 guitarists. They were, technically, among the top in their fields. It is just factually inaccurate to list them among the worst artists of all time.
I would also point out that the list does not include the Starland Vocal Band, the group that gave us the heinous lyrics "gonna find my baby, gonna hold her tight, gonna grab some afternoon delight..."