As far as completion percentage goes, for QBs that started at least 8 games in the 2008 season that was Derek Anderson (started 9 games) of the Cleveland Browns who had a 50.2 completion percentage on 142 completions in 283 attempts.
The 2008 Browns were the only team in the NFL that season to have a team completion percentage of under 50 percent. Brady Quinn started 3 games and had a 50.6 completion percentage (45 completions in 89 attempts), Ken Dorsey started 3 games and had a 47.3 completion percentage (43 completions in 91 attempts), and Bruce Gradkowski started 1 game and had a 33.3 completion percentage (7 completions in 21 attempts).
Matt Cassel, sacked 47 times in 2008.
Ben Rothlesburger Ben Rothlesburger
In 2008, it was 29.1
For the 2008 season, it was 80.1
Brett Favre had 269 consecutive starts through the end of the 2008 season.
The Quarterback does...
The most winningest quarterback in the NFL is Brett Favre with 186 wins
Through the 2008 season in the NFL, that is Brett Favre with 310 career interceptions.
In the NFL, that was Matt Cassel of the New England Patriots who was sacked 47 times.