To be honest its pretty obvious the 2 universities are avoiding competition with each other, they always seem to offer slightly different courses, eg
Economics/Economics and Management
Straight Philosophy/Joint Honours Philosophy
Nat Sci./Straight Sciences
Compsci via maths or natsci / Comp sci from year 1, or joint honours maths and compsci
So in reflection, Cambridge is probably academically top for nearly all the courses, (Baring only English, History, Languages and Law,) and Oxford is top for nearly all its courses (baring Maths)
im not sure about some minor courses eg Arch + Ant, Geography, Theology and Oriental Studies.
To the OP: Oxford is miles better at politics. Oxford graduates have utterly dominated the political scene of the Uk over the last century (probably more)