Prince George Public Library
I visited the teen website of the Prince George Public Library, http://www.lib.pg.bc.ca/teens, which is still being built up, but they seem like they are really on the right track with this site.
The design of the main page is anime-inspired, with a simple layout featuring some manga-style teens, as well as a photo of the library's youth advisory board. There are a number of book lists in a variety of genres of interest to teens, such as vampire books, chick lit, and fractured fairy tales. Some of the "genres" may be slightly mislabelled - I am not sure what they mean by "those teenage years" or "not everything is as it seems..."
They do also have a separate page for graphic novels, which is divided into YA and adult titles. As their graphic novels are not catalogued, these pages contain directions to find the graphic novels, as well as a list of series. They also provide a list of links for graphic novels (at the moment, there are only three listed, but all three are good), as well as a list of books the library holds related to drawing your own graphic novels (these titles are not hyperlinked to the catalogue, which I think would be helpful, as they are all catalogued non-fiction items).
The teen site also contains "entertainment" links for teens, which have a good collection of resources for things to do in Prince George (or "PG" as they seem to call it), as well as external sites such as Much Music, MSN, and Famous Players. Their "homework" page contains links to on-line resources such as dictionaries and encyclopedias, as well as the all-important "ask a librarian" link. Their section of "weblinks" is kind of confusing to me - these are links to to sites related to health information, job resources, and also a section for book lovers. This section might be better labelled "resources" or something like that.
There are also pages for their youth advisory board, as well as a page of resources for parents and teachers, as well as a page of recent book reviews.
The design of the pages is consistent, but I would add maybe a coloured background and some more images to the various pages - even just some shapes or something. It is all very basic with a white background, red menu icons, and the same anime characters on each page under the menu. Even if they changed the anime characters' presentation so that they have different "looks" depending on what the pages are about?
Overall, I think that the PG library is well on their way to developing a very useful, friendly teen space.