With all these Hikki covers being thrown around (as they deserve to be, ugh), I'm very surprised THIS hasn't yet been posted. Her most horrible cover, I'd say.
Also, these:
One of my favorite singers, KOTOKO, has a lot of un-gems.
I think those will do for her part.
Oh and Saori@destiny. The much-hated (for a reason though, I admit) Sunrise/Sunset ~LOVE is ALL~ cover looks like HEAVEN (pun totally intended) compared to some of these.