Gigabyte is every bit the quality of Asus, if not better, so don't discount them. The budget comment is definitely something to consider, though. The memory doesn't matter much, as long as you go with a reputable brand. Crucial would be the best in your list, but the others would be fine as well. Add Patriot to that list and see what their prices are. I'm running nearly exclusively Patriot memory because they've been cheaper than the rest.