There are quite a few. I've tried several, including Panda, and probably the best I've found is Sophos, developed by and for Oxford University. Great for a commercial installation but when I last checked the affordable domestic version didn't update automatically. I use Bullguard, which I find very effective and which is updated automatically. It cost me US$90 for three years, which is so cheap it's trivial.

Many anti-virus applications, including Bullguard, are anti-malware of any sort. Spyware is increasingly at least as serious as viruses, and the free ones such as AVG don't check for that. And they also usually include a firewall, to help prevent people hacking into your computer.

The only anti-malware software I hate and distrust and will not use is Norton. I have used it in the past and found it severely wanting. And well-nigh impossible to uninstall when I wanted to get rid of it.

One other thing about anti-malware software in general. It can only protect you from threats it knows about, and by definition the bad guys are always ahead of the game. Even with the best automatically updated protection software it's still perfectly possible to get malware onto your computer, if it happened before the protection software had been updated to deal with it. This can happen during normal internet access, or if you're not connected to the internet and plug in a flash drive that's come from an infected computer.

One professional office in San Pedro recently had at least 4 different viruses, because they gave me a flash drive with a file I needed that Bullguard found 38 instances of them on. They were running anti-malware software but they thought that protected them and they didn't do a periodic scan of the complete machine. So it is ESSENTIAL that as well as ongoing real-time protection you do a full system scan periodically, I'd say at least once a week. Make sure to scan all external drives (flash drives, hard drives, etc) that are ever connected to that machine. And always scan an external device you plug in before you start copying any files.

If you use Limewire beware that it's used by many bad guys to spread malware. After downloading anything scan it before doing anything with it, and scan your whole machine directly afterwards.