You cant go wrong with either as a brand on your CV. As you want MC work, PwC would have the edge (slightly) and if they'll sponsor you through ACA then bite their arm off. But then the training at Accenture is absolutely first class. Either will polish you to a mirror like shine. Assuming no big commitments from either around certifications, compare money on offer, because once your grad scheme is done you'll want to move on anyway, probably to the one you didnt join now.