The best internship is the one where the caseload consists of what you are interested it, it is in a place you want to live, and with people you get along with. Such criteria differ greatly from person to person. There is no real "best".
Something else to keep in mind... if you are looking for a "surgical internship", these generally require completion of a one-year rotating clinical internship first. As I understand, surgical internships are becoming more and more common to prepare applicants for surgical residencies, especially in academic settings.
Is anyone applying for a Small Animal Surgery Residency? I know the University of Missouri has gone outside of the match this year and Texas A&M is not offering a residency this year so the the difficulty of matching has increased. I suppose given the state of the economy it is fortunate more universities haven't refrained from offering a residency.