Contrary to popular belief, the Vice Presidency isn't a particularly effective stepping stone to the Presidency (except in cases where the President dies while in office!). Here's an Encarta article with some statistics -- which mostly belie the author's concluding sentence.
Sixteen vice presidents have run for the presidency since the founding of our Constitutional system Of those, only four won the presidency immediately -- John Adams and Thomas Jefferson, the first two vice presidents; Martin Van Buren; George H. W. Bush -- and Richard Nixon won on his second try. Five successes out of sixteen attempts isn't a very impressive statistic (seventeen attempts, if you count Richard Nixon's 1960 loss).
Most vice presidents are low profile and don't get to do much while in office. When they run they're generally loaded down with the baggage of the previous administration, and I think the presidency changes hands from one party to another more than half time time if an incumbent isn't running (stats, anyone?).
Fifteen senators have gone on to serve as President. I can't find stats on representatives or governors who have done so (I'm sure there's a lot of overlap). As far as I know, only one president has also served on the Supreme Court: William Taft (who was also the fattest president).