MyList = favorite, basically. You can create and manage them in your MyPage, then add videos to it. General ranking's default is set to rank how many people registered their song to their MyList. You can also set to open your MyList to the public so others can see it, which is what a lot of the uploaders do so others can find their other uploaded works easier.
MyList examples:
shu-tP's MyList /
シンP's MyList /
My KAITO vocaloid MyList </shameless_plug>
Another P gone crazy due to spring.
【初音ミク】PrincessBride!をミクが歌いながらうｐ主が踊ってみた
The song is... GOOD, too. But can't concentrate... xDDDDDDDD