What kind of Nvidia graphics card should I get?

I need to get a graphics card to upgrade my computer. I'm running a HP-pavilion model NP249AA-ABA p6127c with windows 7 installed.
I need the graphics card to successfully run programs like Maya, Mudbox, and unity. Especially Mudbox!

It would also be nice if it could run portal 2, half-life 2, the stanley parable, dead space, and octodad. I'm barely able to run minecraft on this thing. The current graphics card is Intel(R) 3100 (Intel(R) G33/G31 express Chipset Family) And its just terrible.

I'm looking for a Nvidia graphics card. Currently I'm looking at the Zotac Nvidia GeForce GT 640 2GB Graphics Card.
It needs to be affordable. Preferably under 100$.

Guest

If you are using Maya then atleast you need to buy Nvidia GT 650 GDDR5

Chad

Instead of gt 640 get the radeon hd 6670… Gtx 650 would be also a good choice if you can stretch your budget

Hope i helped u

Gaurav