Mine after QB is LT, passrusher (can be a DL or LB), CB, DT or NT, RT, C, the other CB, WR, RB, LB, G, S.
This can vary because of where your production is coming from and who the player is. Urlacher for example I would rate a lot higher because he is so good in pass coverage he stays in on passing downs where a lot of LBers come out on third and fourth downs.
I rated passrusher right after pass protector because the NFL is a passing league and one protects the most valuable player and one is trying to take him down.
CB because a good one can take his half of the field and force the offense to go the other way and that allows the defense to help the number 2 CB.
DT or NT because disrupting the offensive line is so important.
RT, C, because they make everything else work.
WR and RB I ranked down a ways because I believe a good OL can make average rb's and WR's look good.
LBers because there are so many good ones that it is easier to find them than the other positions.
Safety for the same reason as above.
Guards (despite this free agency period) are generally the easiest spot on the OL to fill.