Maybe it's just me, but I got some great added size to my chest from doing essentially one handed flies on a cable crossover machine. I'll try to walk you through this.
Face the machine and grab the cable with your left arm extended. Now turn 45 degrees to your right so your shoulder is open. When you bring the cable across keep your arm extended and make sure to go past the middle of your chest, essentially closing your shoulder.
The main reason I like that is because I can hit a part of the chest that I can't with flies. If I'm really trying to burn my chest out I'll mess around with the angles until I'm exhausted.
im definitely going to try this. looks like you get a better range of motion with this type, especially when you do flies and those dang weights clank onto eachother.