The Cardinals have some issues with there offensive line... We played them in the dress rehearsal a couple of weeks ago and they just couldn't block Mack.The Cardinals were doing some really good things before Palmer got injured last year, I believe they were undefeated with him.
I would say the Lions but I'm biased because they're my team, I do think we're becoming a nicely rounded team though.
Going slightly rougher than those two, I would throw the Rams out there. Should have a bad ass D, just a matter of what they can do on offence.