Especially w/ Windows 8, there exists no real need to go looking.
MSE, as Windows Defender, is embedded & ON, by default. My company recommends this. And the native OS Firewall.
Also, recommend Malwarebytes & CCleaner; SpywareBlaster does no harm, either.
This, also, eliminates a need to buy anything additional, in this context, w/ Windows 8.
Best I could recommend that one can download for free... MSE; not necessary w/ Windows 8.