Dumbbell flyes only work for about 4 inches in the range of motion, once it goes to a certain degree, you're just pulling them in, and most of the weigh is being held by your joints instead of the chest muscle, bench pressing and incline bench pressing locks your arms in a certain position where it forces your shoulders and triceps to do a lot of the work instead of hitting directly the chest...this is my routine and it works nicely...
2 sets 8-12 reps incline dumbbell press
2 sets 8-12 reps flat dumbbell press
2 sets 8-12 reps decline dumbbell press
1 or 2 sets of cable cross overs
1 or 2 sets of peck deck flys
Again, the proble here is that you are not effectivle working your total chest. You should do something in the sagaital plane of motion, all you exercises are in the transverse plane. How about doing dumbell presses but with a neutral grip, keeping your elbows in. That will change the plane of motion and the stimulus entirley. Also why not do some decline bench press?? The reason I like decline bench press is because the angle in the bench is settign you in a plane of motion right inbetween the frontal and the transverse planes. This is good because you are getting not only some shoulder adduction (frontal plane) but also horizontal flexion (transverse plane). I like this because the adduction stimulates the sternocostal portion of pectoralis major while horizontal flexion works the clavicular portion of pec major......the best of both worlds.
i had the same problem a while back. until i started to pinch my shoulder blades together when i do my chest exercises. this puts alot more stress on your pecs. give it a try. i think you'll notice a big difference. you'll prolly have to lighten the weight up a lil bit but its worth it.
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