Spy Sweeper is rated #1 in many areas.

"Spybot - Search and Destroy" is pretty excellent (and it's got a name with attitude )

I use ad-aware from lava soft

Ad-aware is a program for eliminating ad programs. Not for spy-ware. So far(20 yrs.) of dealing with this type of stuff in a professional and homeware type of environment. If you want to eliminate spy-ware versus ad-aware, those are two different type of programs. As are Virus's.

I just recieved my friends computer and spent half a day eliminating virus's from his computer. I recieved 20 dollars for this. It wasn't the money it was the challenge. (could I clear his comp. of virus's or not? I DID)

Breathing an air of satisfaction.

I use Avast which is a free complete internet defense suite. I started using it when the AVG suite started having problems and I did some research on alternatives. I am happy with the change.

Spyware Doctor by PC Tools.

Mac OS X!

Many of the software listed here are the 'classics', e.g. Spybot S&D, Ad-Aware, etc.

Two new, but very good ones are SuperAntiSpyware and MalwareBytes Anti-Malware.

Hope that helps.

Edh: um..."ad ware" is spyware. Of course I've only been doing this for 31 years. Not that, that means anything. Except for general principles, any knowledge of technology older than five years is "trivia".

Wouldn't it have been easier to have your friend restore from his regular backup?

Pepka: Don't cheat! Some of us like to work too hard. Can't make a living supporting Macs. Not enough things go wrong.