Let's quickly name famous names that starts with M. Madonna, Michael Jackson, McDonalds, Michael Jordan, Mr T... (hmm Michaels may make another list).
As oppose to perhaps the letter N, the letter after M. Nelly, Neo... not much. How about L? Lenny... J is not bad, especially if you are Jennifer.
So a quick math taking M, against the number of names available, against 26 letters, not including names that start with !. It should be about 21.4%; that M rules.
So if you are thinking of changing your name, how about on that starts with M? Mandy sounds good.... oh... Mandy Moore!