Depends if you would like it to be internal or external.
Internal, I recommend:
http://www.newegg.com/Product/Product.aspx?Item=N82E16833124115External, I recommend:
http://www.newegg.com/Product/Product.aspx?Item=N82E16833124126Personally, I'd recommend getting the external adapter, as it's so much more versatile (easy installation, easily portable).