Um. Tarvaris Jackson didn't even start for Minnesota last year for the league's 25th-best passing offense, whereas Romo led a Cowboys' passing offense that was statistically one of the top ten passing offenses in the league (and Romo missed three games as well; the three games he was out, the Cowboys' offense was beyond putrid). Looking at per-season averages, Romo trumps Jackson in every relevant passing statistic category, and he has more wins and a better winning percentage.
I honestly cannot believe that I'm having to argue for Tony Romo over Tarvaris Jackson.