This is my current Graphic card, here's a link which shows it:http://www.newegg.com/Product/Product.aspx?Item=N82E16814131462
If you think it's not good for gaming ( games like GTA IV, the sims 3 with expantions, etc.) please suggest me a good, high performance, reliable graphic card.
my budget is around $150
I like Nvidia brand much better than AMD. So I don't want to buy an AMD again.
Its not AMD fault that you are disappointed with the 6570. It is a weak card and may have been bought with wrong expectations. There are other AMD cards suitable for your need but admittedly, at your budget & what's currently in the market, the 460 recommended is best bet.
But in any case, even if you do not like AMD as much as nVidia, keep the 6570 as it may come handy someday.