Poking around AT's archives, we found this good question that we totally related to: How to hide the monstrously ugly a/c unit?
In our bedroom, there's a wall unit that we've never used (and probably won't), but we are reluctant to deal with its removal just yet. The issues evened out, though, as my husband and I had a giant mirror that we weren't so confident hanging (this sucker is massive and heavy).
Our solution came without thinking much about it - upon moving in, we propped the mirror against the wall, in front of the ugly a/c. We liked the look and the ease of the solution, and still live with it this way six months later.