How's the 4770 better? because I noticed that it's running 128-bit compared to the 4830 which runs it at 256 bit

It does run GDDR5 compared to the GDDR3 in 4830 but does that make that much of a difference? From what I hear anything past GDDR3 doesn't make significant differences right now, or am I wrong?

I'm planning to build a new computer, and the only thing I'm debating about is the videocard. I'm having a hard time figuring out what the best budget video card out there is currently.

My budget is around $100 dollars for the GPU. I'm going to be building a gaming PC, but not so crazed up on framerates. Just want to be able to run Cod4, L4D, TF2, etc at around high or smoothly. Any suggestions?

benchmark links or newegg links would be helpful after recommending a card.

thanks in advance!