Simple format. First picture is of the anime you watched, second is of what you thought it would be like, third is what it was ACTUALLY like.
post your own, you can host at tinypic or imagepile or whatever.
Kodomo no Jikan, expected something like Dateline's to catch a predator, ended up with a show about how to deal with children who have emotional problems.
Step up Love story, expected porn, got sweet story of married couple first year.
Chi's Sweet home, expected hamtaro crap, got pure awesome (as symbolized by ninjas with guitars)
And so on, and so forth try your own?