We have over 5000 mentors, so this is a very hard question to answer. You can see your local mentors by going to http://fi.co/mentors, and new mentors are added very often. 

Many mentors also have local experience launching startups. For example, our best mentor in Silicon Valley, will not typically be an expert at launching a business in Singapore. Our most experienced mentor in launching startups globally then, would be our CEO, Adeo Ressi.