best grphics card

I am looking for a good graphics card for gaming. I have seen these cards and would like advice on which is the best?
EVGA GeForce GTX 660 Ti FTW+ NVIDIA Graphics Card w/Backplate- 3GB
EVGA GeForce GTX 660 Superclocked+ NVIDIA Graphics Card – 3GB
MSI GTX660 Ti PE OC NVIDIA Graphics Card – 2GB
EVGA GTX 670 FTW NVIDIA Graphics Card – 2GB
I dont know if they will fit in my machine as I do not know the size, how do I find out?
At the moment I have a gforce GTX 295.
Thankyou for any help or opinion you might have.
..
Answer #1
my pick will be this one:
EVGA GTX 670 FTW NVIDIA Graphics Card – 2GB
because of its Memory Interface having 256bit good for gaming
and the card’s length is 10 inches
Answer #2
1. Find more information about your entire computer setup, CPU-z, open case examinations.
2. Gather:
Cpu
GPU
Memory
Motherboard
Power Supply
Case
3. List the information here.
Answer #3
They run some tests on those cards here..
http://www.hardocp.com/article/2012/09/03/msi_gtx_660_ti_power_edition_oc_video_card_review/1
You might need to google around a bit to find the length of a brand you want.