The Buffalo Bills fortified their defensive line with two free agent signings this off-season. By adding ten-sack end Mark Anderson and $100-million man Mario Williams to a line that featured 2011 third overall pick Marcell Dareus and Pro Bowl member Kyle Williams, the Bills turned a weakness into a presumed strength.

Most observers believe the Bills' upgrades along the defensive line had made it the team's strongest unit, at least on paper. Would-be starters in years past provide solid rotational depth behind this season's starters. The question we want answered today is this: which unit is the most complete other than the defensive line?

My brain immediately split into two ways of thinking. Do I answer the question based solely on the starters, or does overall depth play the more important role? Obviously, both are important over the course of the season.

Ultimately, the Bills have one other position that is pretty stacked with talent and role players. With Fred Jackson and C.J. Spiller carrying the load, Corey McIntyre and perhaps a surprising Dorin Dickerson contributing from the fullback position, and Johnny White and Tashard Choice competing for depth, the running back position has talent at the top and options behind them.

You could argue the offensive line here, with four established starters, a pair of youngsters battling for the fifth spot, and adequate depth built through the draft. Or perhaps you're partial to the secondary, with solid safeties and some talented youngsters vying for cornerback spots with veteran Terrence McGee.

I'll go with running back, but I'm not the end of this conversation. What unit is second-best in your mind?