Spreadsheet Page Blog
I ran across a site that features an add-in that provides an alternate MsgBox function: ktMsgBox. Here's the UserForm (click to see it in actual size):
I'd say that qualifies as a poorly designed UserForm. Besides being ugly, it's just way too confusing.
When designing a UserForm, my advice is to emulate the look of the dialog boxes in Excel as much as possible. Just because you can change the colors and cram 50 controls into one dialog box doesn't mean you should do so.
I downloaded the add-in just to see how it worked. I deleted it as soon as I saw the pop-up greeting that stayed on screen for 60-seconds and couldn't be closed.