All right, both laptops have pretty much the same specs... The Y580 and the GE60. Both are 15.6 inch laptops with a 1920x1080 resolution. Both have 3rd gen core i7 processors and NVIDIA GTX 660M cards. The problem with the Y580 is that it comes with a default RAM of 2GB and can be upgraded only to 8GB. The GE60 can be upgraded to 16GB. I THINK it's default is 6 or 8GB. Can't remember. Anyway. If you had to choose between these two, I'd choose the GE60, because it's hard drives have the option of running at 7,200 RPM as opposed to 5,400 RPM. However, the problem is that it is more expensive than the Y580 by at least $200. So ask yourself if it's worth the $200 more for pretty much the same specs.
Also, the gigabyte p2542g is well over $1,000 and Y580 is the best gaming laptop in the under $1,000 range.