TTM seems to meet needs pretty well if you are only looking for something basic. It doesn't seem to be as customizable as the one from OpenCube, but the company behind it is a lot more friendly. If you decide to use this menu on your site, make sure that you have a good knowledge of how to make recursive arrays with Javascript. If you plan to dynamically generate your menu using a server-side script, you are certainly better off with the one from OpenCube, because dynamics with TTM can be hell.