My personal peeve is door handles.

You know what I mean, you come to a door and you don't know if you should push or pull. It happens to me almost everyday at work when I'm deep in thought.

"The Design of Everyday Things" by Donald Norman, nicely sums up a lot of design problems. Even tho the book was written in 1990 or earlier, we're still facing many of the same design problems.

Everything2 sums up the book nicely: http://everything2.com/index.pl?node_id=140365