I'm assuming you're asking about themes for self-hosted WordPress sites. I don't know if you are interested only in free themes, but if not, I highly recommend using the Genesis framework by StudioPress with one of their child themes. As far as I know, most if not all of the Genesis child themes accommodate two menus. They also include a custom menu widget that allows you to place a menu pretty much anywhere on your pages.
For my own websites and client work, I use Genesis and usually pair it with the Dynamik Website Builder child theme. This is only appropriate, though, if you want to do a customized design, because DWB is more like a "blank slate" than a polished design. Its great advantage is that it allows you to easily make design and functionality changes to your site without writing code. But there is a bit of a learning curve.
If you want something that you can use "out of the box" with maybe just a little customization, Genesis has a good variety of really nice child themes suitable for all different types of sites. They have solid coding, with good support both from StudioPress itself and from the user community.