The navigation in Claire Baxter portfolio is disposed in an apparently random and untidy way form that indeed anticipates the faux shabby style by which the entire web site is organized.

Interesting the combination of tabs and drop-down menu in the navigation menu of Inkd: tab indicates the main sections, while the drop-down menu (on mouse over) allows you to see all the subsections. 
Even the color code is accurate: active tab is white, blue tab are those relating to the product itself, while grays tab are dedicated to [...]

The navigation menu of this web site about Tara Hunt book’s The Whuffie Factor, is cleverly funny (the book is about online social networks).
As you can see from the screenshot, the over and the selected state are identical.

Times Online’s breadcrumbs start with the Hamlet question “Where am I?”.
The navigation menu effectively indicates to which level of navigation and section the page belongs to.

Creattica, s showcase of design and creation of prolific Evanto, shows  unusual tabs
For those interested, I remember reading a tutorial on the subject on Psdtutsplus, a  famous web site dedicated to Photoshop. Obviously branded Evanto.

Changing the text in the menu with a photo is a nice idea.
A quick loading in Ajax appears the first time you load an image to prevent unpleasant effects of vacuum.

The dropdown menus in Sourcebits are drawn as metal tabs, Apple style, which contain tiny icons.

Using oriented vertically texts in web. sites leaves me puzzled 
I think this treatment should be reserved either in situations where the overall dimensions make it absolutely necessary or for short texts (e.g. often you see the Feedback button oriented vertically).

The language selection menu on BootB is rendered fairly special: all the options are already exploded, instead of being enclosed in a drop down menu.

Unusual shape for the tabs on Mywire, an aggregator of contents, news, post.

I like the site menu on Ifinstanbul (a turkish film festival) web site:  each menu item has a color which is used also for  layout and text elements.

I love the way these tabs smoothly change of color when you hover on them.

A classic horizontal tab navigation with 3 different states (selected, normal, mouse over) for each item.
Fontshop is the foundry founded by Erik Spiekermann.

Floral menu and  layout for a company that deals with eco-sustainable projects.

Alltop navigation menu allows you to browse contents by topics or by letters.