I use PC Tools Spyware Doctor with antivirus and Browser Guard.
Last month, corporate IT issued me a laptop to be used for field testing. Because I would be using the laptop off site, they gave me admin authority. It was running pretty slow, so I ran a full scan with the latest McAfee and it came up clean. Inasmuch as I don't have much faith in McAfee, that night I took the laptop home, I used my unused licenses to install the PC Tool software, and also installed their Registry Mechanic.
I ran full scans using both, and it turned up 26 threats, 25 minor, and a nasty little Trojan that McAfee missed altogether. Registry Mechanic found 204 registry errors to boot. After the machine was cleaned, it ran much faster...
I've used PC Tools security software for years, with flawless results. Browser Guard, and its stand alone twin, Threat Fire, provide real time protection, and will block known bad sites. It's a bargain, and you get three licenses allowing installation on three machines.