I've looked at best bits for BB7 and 5, 7 has more view and more comments and is more discussed than 5, and before anyone posts, just to say that its my opinion and its what i've observed.
Best bits of 5
http://youtube.com/watch?v=KcP_6Wv0jM4
Best bits of 7
http://youtube.com/watch?v=Dk6f3CuBRx4