The very best school is...
The very best school is the one which you attend and then pass your exams afterwards - obviously! But the relationship between you and the lecturer is the most important one and maybe going for a "look see" might be worthwhile. However, from what I have heard to date, the vast majority of lecturers are very able chaps and therfore would place them on a par with each other and not be too worried about where you go.