Barack Obama:
Senator Joe Biden of Delaware
Governor Mike Easley of North Carolina
Senator Jay Rockefeller of West Virginia
Governor Kathleen Sebelius of Kansas
Senator Jim Webb of Virginia
Governor Brian Schweitzer of Montana*
John McCain:
Governor Mark Sanford of South Carolina*
Governor Tim Pawlenty of Minnesota
Governor Charlie Crist of Florida
Congressman Mike Pence of Indiana
Senator Joe Lieberman of Connecticut
NOTE: Asterix denotes who I would select if I was the Chairperson of Barack Obama's or John McCain's Vice Presidential search team. However, knowing them they would select some random unknown to "balance" the ticket, such as Congressman Rob Portman of Ohio for McCain or Congressman Earl Pomeroy of North Dakota for Barack Obama.
Not a single bad choice on either of those lists (except perhaps Lieberman). I certainly think Sanford is the best choice (although Hutchison is a great one as well), and Schweitzer would be wonderful too (although I still prefer Easley).