8GB (2x 4GB) Crucial Ballistix Sport LT @ 2,400MHz $149

8GB is plenty for all your gaming needs, especially at 1080p. It’s likely that within the next four years, you may need to double that capacity, but only for the highest of high-end titles. Fortunately, the Gigabyte B360 motherboard supports four sticks of DDR4, so it would simply be a case of buying a second set of the Crucial Ballistix Sport LT featured above and adding it to what you already have.