I have a dell 530s and want a graphics card that will run l4d on med -

well. can you tell us your screen resolution? I have a 9400GT and that could handle it at those settings at like 1024x768 but if you're playing on a 1080p display, you'll need a card that is better and you will probably need atleast 1 gigabyte of vram for hd displays. Also, do you have a specific budget? Preferences(video ports/features)?

What are you computer specifications? The 9400GT isn't a gaming card though, also low profile cards aren't the bst for gaming.

my point was that for such a broad request for a recommendation, even my 9400GT could handle it

Here is one currently the best from ATI http://www.newegg.com/Product/Product.aspx?Item=N82E168...
From the green team http://www.newegg.com/Product/Product.aspx?Item=N82E168...

^ Ya,
also consider a 4670