help with vid card please

hey guys, i recently got this pc, and aparently it needs a better video card.

here are the specs:

intel core 2 quad

q6600 @2.40ghz

1.98gb or ram

videocard: geforce 8400 gs

alright, i wanna be able to play all the cool games, i am a TOTAL PC N00B so im asking whats the right video card for me?, my aunt offered to help me with $185 , but i have another $100, that id rather not spend but will if i have to

i was thinking something with geforce 8800 but there are so many lol, gs, gts, gtx :P

and one more thing, i was looking at new egg, and everytime i searched a video card, the same one costs diferent prices:

http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&DEPA=0&Description=geforce+8800+gt&x=0&y=0

why?

please help!

Some are Overclocked, some are normal, some are open box.

The 8400GS is not made for gaming at all, it's just a cheap graphics card. If you have 285$ and you're looking for a very good graphics card capable of playing many games on very high settings, with a great Price/Performance value and a nice lifetime

http://www.newegg.com/Product/Product.aspx?Item=N82E16814127325

Generally GT is the lowest version, GTS, is above GT, GTX is above GTS, and Ultra is above GTX.

But not always. For example the GT 512MB (G92)'s are better then the original GTS. And the GTS 512MB (G92)'s are better then the GTX's.

(Generally)