That's a GREAT idea, getting a good graphics card; but if you can afford it, it would be better to just get a new computer. Your computer is just not worth updating.
If you can't afford a new computer right now, I recommend getting a graphics card and power supply, then MOVE them to your next computer, so you won't have to buy them again!
Video cards I recommend are the Radeon 7770 at $100 or so, or the 7790, or 7850, or 7870 for $200. Anything over the 7870 gets way too expensive. The 7770 is great for general use, and light to medium gaming. The 7870 would be for heavier gaming. The 7770 is the most bang for the buck, at around $100 (it started off costing $160!). (The Radeon R7-260X is like a Radeon 7790, and the R9-270X is like a 7870, they just cost more, being more recent cards.) The best video card for $200 is the 7870.
The Radeon 7770 and 7870 are now getting hard to get. They are "last year's" card, and are not made anymore. When they are all gone, the choices are the R7-260X and the R9-270X. Both of these are excellent cards. The Radeon R7-260X is like a Radeon 7790, and the R9-270X is like a 7870.
If you prefer NVidia cards, the GeForce GTX 750 is like the Radeon 260X.
Remember, computers are built with a power supply just barely able to power them as they are. A video card of any kind requires an upgrade of the power supply. Even the video cards that don't have extra power connections can draw up to 75 watts from the motherboard. I would recommend 750 watts, major name brand, semi-modular or full modular, 80+ rated, single 12 volt rail, active PFC, and so on. Cost about $135. It's always best to have more power than you need. Power supplies are happiest running below their maximum, and they live much longer lives.
Total cost would be $100 to $200 for the video card, and $135 or so for the power supply.
~Helpful ~Cindy!
