I'm not sure why, but I did go to a Brother Beyond concert once. I think we thought it would be a laugh. It wasn't. Worst album I've ever heard is, without a doubt, Be Here Now by Oasis, Absolute pants. A lady friend recorded it for me, and raved about it. I listened to it in my car, and it was unceremoniously dumped in a roadside skip.
How about worst film?
Natural Born Killers gets my vote. No, hold on a minute. The Blues Brothers. Utter, utter plop.