http://whymtgcardsmith.tumblr.com/
When it comes to custom cards, there's the finely designed - something not out of place in an official set - and the slightly flawed - something that can be slightly corrected. Then there are these cards.
The link above goes to a blog documenting several stellar examples of bad design - be it terrible formatting, lack of understanding how things work, or intricate things that make no sense. Official Un-set joke cards may be equally insane, but at least they are functional.
Blog updates almost daily with a new bad card for us to collectively point, laugh, and/or snark about.