Nvidia doesn't have much low end offerings that is really good. Radeon HD7750 is around $100 or lower. There is a GTX650 which is around $100 as well but it needs a 6-pin power connector indicating it uses slightly higher power. Not a bad alternative though if you found the GTX650 is cheaper than the 7750. After that, the HD6670 is definitely next best choice. Don't get any cards lower than the 6670 for gaming, you'll most probably be disappointed.