Which graphics card is better for gaming?

It mainly depends on the resolution your going to be playing games at. If you are playing at 1080p then you will need the 1gig evga one however if you are playing at 720p or less then the asus 768meg will have no noticeable performance decrease, also you have to bare in mind that the asus 460 has an after-market cooler on it, if you have good airflow in your case then the evga one is ok but the asus one will really shine because even though it will ventilate air inside your case the hot air can easily be removed in a well ventilated case (especially if you have a lot of fans at the top of you case as hot air rises) and generally GPU coolers like this (or the TwinFrozr II design from MSI) do much better cooling than stock ones that exhaust it outside the case.