Let's compare one by one. The main things to compare in a laptop are the processors, RAM and graphics cards. So, processors seem to be the same... RAM is more in the first, but I'm not sure if the RAM can be upgraded... The first has a 2GB 640M card, which is superior to the 1GB 630M card. Screen size doesn't matter too much, except for the fact that the 15.6inch screen will be easier and lighter to move around with than the 17.3inch screen. Lastly, resolution... It is true that the first option has a lower resolution, but it shouldn't matter much because at least where games are concerned, the graphics card will sort out any major frame rate problems. In any case, the difference in resolution isn't ALL that much. So I strongly suggest you go ahead with the first one, because of it's graphics card and slightly bigger RAM. As I said, it also has the added benefit of being more mobile. A 15.6 inch screen is really large enough.