Need help selecting a good video graphics card?

hey i have a emachines t2895 desktop, kinda old, but wanted to update the video graphics card to run games on it better like WoW and was wondering what are some good video graphic card choices. i want something that works well and runs great with high quality because i wanted to later add a blue ray player drive to the computer. please help. i dont know alot about graphic cards and dont know what to look for in a good one. thanks.|||anything by nvidia i like|||what Motherboard, or what slots are open? how good is your power supply unit? with slots are they pcie 2.0? agp? do tell, and i wouldnt go with Nvidia.. they come pre clocked high... ddr3 isnt to shabby.. ATI with their 5xxx series ddr5 directx 11 is vary niez, UNLESS your going with Nvidias fermi wich is comeing out later this year.