i think barbell rows and deadlifts are a must in back routines, deadlifts arent the best for bodybuilders but i believe they build a thick back, and bulid great core strength. also barbell rows are the best when it comes to thickness in the back. i would say the best taht has worked for me is.....
hyperextensions: 2 X 20 (warmup for the lower back, just bodyweight)
deadlifts: 3 X 10, 6, 4
barbell rows: 4 X 12, 10, 8, 8
front lat pulldowns: 4 X 6-12
cable rows: 4 X 6-12
on all sets pyramiding the weight up, also chin ups could work their way in tehre somewhere.