I just remembered one of my all-time faves in this category. For a band that actually wasn't a one-hit wonder, they were amazingly terrible. Any of their albums backs that claim. Everything that wasn't one of their three hits ("Dance With Me," "Still The One" and "Love Takes Time") was completely off-key and unlistenable.
There's a John Tesh x-mas CD stuck away in a box around Rockford's house somewhere. I'm not making that up.
We still own my wife's Richard Marx albums and my Air Supply albums, along with a few old George Carlin and Richard Pryor LPs. And no, they are NOT my Richard Marx albums.
I not only liked the earlier Richard Marx albums, I thought his comeback album 2-3 years ago was very under-rated.