This is fun. Here's another opportunity for you to give me content that I can monetise. What slide crimes can we think of other than..?
Pictures of money when you're talking about money (and the unthinking use of clip art generally)
Pie charts (and 3D charts generally)
I think we can take for granted too-many-words, type-too-small, all those kind of things.
I guess I'm thinking of a slide type which is almost always unhelpful. Got any others?