i have a dell gx 280 small mini tower
with 250 watts psu (i know it sucks but i cant change it)
plz tell me will it run any one of these,
1. 9500gt by inno3d
2. gts 220 by inno3d
3. hd 4650 by HIS
I believe the "small mini tower" is one of the "slim" cases so you will need a low profile video card. Looking up the gx280 your processor is a Pentium 4 or D which are both quite poor for current games. The best card you should bother with that is low profile is the HD5570; http://www.newegg.com/Product/ProductList.aspx?Submit=E...
It is fairly decent for low resolution gaming(1280x1024 and below) although a lot of current games will not do well on your processor, especially if it is a P4.
It should be ok for a 250w Dell PSU.
The HD5570 would be a good choice at that resolution. Just don't expect miracles on cpu intensive current games. In fact considering it is a P4 I'm not sure how much practical difference you would see over a card like the HD4650 if you would rather save some money; http://www.newegg.com/Product/Product.aspx?Item=N82E168...
I would rank them as follows;
HD4650 > GT 220 > 9500GT
However all of them come in versions with DDR3 or DDR2 memory. If either the HD4650 or GT 220 are DDR3 then get that. The DDR2 HD4650 is probably roughly equal to a DDR3 9500GT.