Just incase anyone doesn't know the difference between a serif and sans-serif font:
![Image](http://upload.wikimedia.org/wikipedia/commons/thumb/2/26/Serif_and_sans-serif_03.svg/209px-Serif_and_sans-serif_03.svg.png)
If you really like the metro font then maybe transferring the legends and continent names on the map to a sans-serif, or even the metro font itself will help bring the title in more. although I still argue that the metro font doesn't fit with general aesthetics of the map.