Thanks for the replies. Nothing wrong with the current card, except it's lacking an HDMI output.
I'm still learning about video cards...what numbers show that the 7900GS is more powerful? Obviously, for my current 256MB card to be better than those cards (512MB - 1GB), other numbers must tell the story... Is it the 256-bit bus width of the 7900GS vs. the 64-bit bus width of the other cards that contributes to making the 7900GS better?
No its the overall performance of the cards, it doesnt matter whether or not the memory is larger its the stream processors/shaders/cores/speed of memory that matter. Even then an older card might be faster than a newer one. The 8400gs is slower for example than a 6800gs. http://www.tomshardware.com/reviews/best-graphics-card-...
A 5450 is equivilant to a 7600gs according to the chart.
This would be the best card for your money by far. 9800 gt is about 2.5 times as fast as a 7900gs and it supports dx 10 for 49.99$ it would blow the 8400gs and 5450 out of the water in terms of game performance.