The 'secret' to conversion - and site navigation clicks should be considered as micro-conversions - is to make a visceral connection with the visitor just as with any other call to action:
* literally grab their attention.
Remember that most are scanning on the fly-by and you need to interrupt that process.
* dose with emotion.
Remember that unless you can initiate an engagement process the visitor is likely to return to their default scan and away process.
* encourage memory retention.
In one sense inherent in being persistent site navigation.
To what level you need or should take the above framework will depend on you, your niche, and your audience. It can be as simple as replacing 'About Us' with ' About EGOL'* or 'Who We Are'. Or it be somewhat different: 'Our Vow' or 'Hi, My Name Is EGOL'* or 'Who Is EGOL?'* or a simple 'EGOL?'*...
The most important part of unusually naming persistent navigation is that each link name (anchor text) be consistently appropriate with the rest. Thus if using 'Who Is EGOL?'* an appropriate companion link might be 'Where is EGOL?'*.
* Note: The EGOL name is used without permission on grounds of being shorter than [insert brand name]. And unlike Waldo is not trademarked.
Most often sites persistent navigation defaults to very similar naming conventions due to length restrictions; all those links needing to be squeezed into one constrained horizontal container. It means that being different from what visitors expect to read is (1) good because it sets your site apart and it becomes more likely to be remembered; and (2) bad because being different will cause confusion while the mind adapts and possibly dislike - some people distrust the different.
Probably two-thirds of my sites use rather bland default persistent navigation names while a third use mildly different naming conventions. And I can't say that I've noticed a difference in visitor behaviour or usage. No really wild or off the wall ones though.
Sooo... feel free to test and get back to us... Mmmm?
However, page titles, headers, sub-headers, captions, buttons, et al are definitely conducive to 'zingers' and similar that follow the framework I mentioned at the top of the post.