Just looking over 2014 season records between these three conferences. According to my review here are the records:

ACC vs SEC 4-1

BIG vs ACC 3-1

Big vs SEC 1-1

You can argue that some of the SEC teams were not at top, but MIZZ won the East and lost to Indiana, which claimed the BIG east basement.

You can also say that Wisconsin lost to LSU, but remember that WI had some QB injury problems at beginning of season and that Melvin Gordon did not play much of the 2nd half despite running wild on LSU in the first half. Despite the injuries, WI barely lost.

Although I admit the SEC is a good conference, so are the other major conferences. Too many people automatically think the SEC needs to be put on a pedestal based on a lot of hype. Bottom line is that much of the SEC Magic is perception and great marketing.