No such thing. Only a top 25. Mainly because there is no human polling beyond a top 25 plus whoever gets points fills in the next 8-10 spots.
I actually like a flexible playoff that adjusts to the season, unfortunately people would be scared to implement it. But if you consider wins AND losses, the year Bama beat us for the NC, their loss was probably the best loss of the season because we were badasses and #1. Who had a better resume to play us than Bama? I'd probably still throw them out ideally as the SEC is represented by LSU and we beat them head to head, but a great case could be made for Bama, especially in a two-team "playoff" like we've had with the BCS.
Anyway, I do think its possible to keep the regular season important but the powers that be aren't open minded enough for it.