joe3, the brothers above have advised you well.
i have a 4670.
Return the 4350 IMMEDIATELY; the 9600 GT is worlds better than it ,and so are all the cards mentioned above, i.e. 4650, 4670, 5570, 5670.
The GT240 is between the 5570 and the 5670.
The 5670 is alot better than all the cards maentioned so far, except the 5750, which is alot better, but it's too much for:-
1 - your monitor's resolution
2 - your Power Supply
3 - you budget
The 5670 is perfect as:-
1 - max any game you play at that resolution.
2 - NO EXTERNAL POWER REQUIRED - it will draw all its power from the motherboard.
3 - great performance for the price.
Btw, which processor do u have?