Good cpu with a gtx 550ti

I have a gtx 550ti (gt on sale for 130$) but i have it pared with a athlon ii x2 at 3.6ghz. I think i have some bottle necking going on. cpu is at 100% usage but gpu is only 50-70%. so what would be a good cpu to upgrade a limited 95watt mobo. I was either thinking
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
or a
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
but overclocking it to 3.1ghz. so what does anyone think for playing games like Bfbc2, crysis 2 black ops and eventually bf3 (witch i heard will use up to 8 cores)