The GPU is the most important part when determining game performance. The 610m and 635m are not that great at gaming. They are better than Intel's integrated graphics, but not by much. If you are playing less demanding games like Source engine titles, or Call of Duty, and aren't cranking the resolution up too high, the 635m will be adequate. However, with laptops you cannot upgrade the graphics later on, you are stuck with what you buy. If you really want to game on a laptop, you need to go all out and get the best GPU you can afford, otherwise you may get stuck with a paperweight in a year's time that can't play the latest titles you want.
well i thik you should be fine with the 2nd one if you only aim for games like guilt wars 2 but i think the 1080p resolution will play a bad joke on you. Guild wars 2 isn't that demanding but i think that laptop vill hadle it just fine with a bit of OC but be careful laptops don't oc very well and you might risk blowing up your PC.
i'd suggest going with one the asus g-series or the lenovo ideaPad y570.
the g-sereies is the best but more expencive, though the ideaPad is great too. i'v heard you can run bf3 pretty well with both of them.