I never have the same workout on chest day as the week before, well as far as sets and reps. Usually I do:
5 x 5 flat barbell
4 x 8-10 incline dumbell
3 x 12-15 flat flye
Some days, I may do 3 x 3 on flat and more reps on incline...I guess it just depends on how I am feeling. For the most part, I try to accomplish what I posted above.