Need graphics card advice?

[godoftrees]

i can game perfectly well but on some its either laggy or i need minimum graphics to play it, i want to change this so help me out here:

Windows 7
Emachines 64bit
AMD Athlon ll X2 220 dual-core processor
NVIDIA GeForce 6150SE graphics
DVD-Super multi drive
500GB Hard Drive
4GB DDR3 memory
Multi in one media card reader


take a look here and tell me what you think the problem is, i believe its my graphics card, if it is please let me know what would be the best possible cards to upgrade to. If its not please let me know what the problem may be, thanks for help!

note games i'm having issues with(if that helps):
left4dead 2
Perfect world
Black and white 2
minecraft (i'm forced to put my render to short)
Allods online

 

[Trotter]

What's your potential budget?

 

[godoftrees]

around 200 or less maybe a list of some that would be great !

 

[godoftrees]

something like 1-200 but i would prefer below 200

 

[Sean W.]

how many watts is your power supply?

 

[Fat.Clown]

OCZ ModXStream Pro 600W Modular High Performance Power Supply compatible with Intel Sandybridge Core i3 i5 i7 and AMD Phenom
$10 off w/ promo code EMCJHKD43, ends 12/12
HIS H677F1GD Radeon HD 6770 1GB 128-bit GDDR5 PCI Express 2.1 x16 HDCP Ready CrossFireX Support Video Card with Eyefinity
Free Dirt3 game coupon w/ purchase, limited offer

 

[godoftrees]

where can i find this information? i tried putting in my emachines register code on my computer but it was invalid

 

[Trotter]

eMachine = 250W or less power supply.