What should be on the top bar of a Web site?

The top bar of a site shows links that the user uses a lot.

Here is Stack Exchange's top bar:

This shows links that are of interest for the user:

These are the links that are the most important to the user, hence they are at the top of the page ^[1].

I'm designing a site with the following menu items:

What items should be on the menu bar, and what should be in the menu?

^{[1]: by default they're sticky, but there's an option to turn them off.}
^{[2]: yes, a menu button on a menu bar.}