Dropped passes are a difficult stat to locate, but in 2006 I'm fairly certain it was the Indianapolis Colts.
indianapolis colts
Cleveland browns
New York Giants
Minnesota Vikings
The Kansas City Chiefs, with more than 50.
terrell owens
Braylon Edwards lead the NFL with dropped passes in 2007.
myles Austin
Randy Moss
33 dropped passes. Second most in NFL for this year.
Braylan Edwards (NYJ) formerly Cleveland
Ravens