I recently finished re-reading the Harry Potter series, and I found myself reflecting on the portrayal of the Hogwarts librarian, Madame Pince. A minor character in the series, she unfortunately embodies many negative librarian stereotypes--unfriendly, extremely strict, and decidedly unattractive ("vulture-like" is one description found in the books).
To J.K. Rowling's credit, she actually apologizes for this characterization, which was for purposes of the plot rather than her actual perception of librarians.
But anyway, I got to thinking about depictions of librarians I've come across in other films and books. One favorite is Mrs. Phelps, the kindly librarian in Roald Dahl's Matilda, who encourages and cultivates Matilda's love of reading.
Another fun one, which I came across more recently, is from Neil Gaiman and Dave McKean's MirrorMask. Although the librarian is a shusher, he does prove to be helpful and you get the feeling that he's probably not as grumpy as he acts. And hey, bonus points for the librarian being a guy.