Exit opportunities: Google vs. McKinsey

So I just graduated from undergrad and accepted an offer to work at Google, in their Dedicated Client Services division (it's like account management with their big advertising clients)... And Google from what I've heard, read, seen and the reactions that I get from people when I tell them I'll be working there, has shown me that Google is an amazing place to work... Culture, perks, etc... But I have recently been presented with an opportunity to work at McKinsey & Co., which is also an amazing place to work. I interviewed with a ton of I-banks and BCG, and Bain during the fall, but ended up with a job at Google... So now that I have to make a decision between the two, the biggest thing for me would be which company has better exit opportunities??? I wanna make the best decision for my future and not just what looks good for now... Any thoughts?