I had Webroot Spysweeper installed by Best Buy, it does a good job, downside is it's not free. Although, Adaware is also very good, I still catch things with it that Spy Sweeper misses sometimes. And, it is free.

For viruses I use Norton AV. I used to have AVG as well, I was quite shocked when the guy told me that having more than one Anti Virus running is actually a bad thing, I guess they tend to cancel each other out. Don't know how much truth there is in that, but, since it didn't make the guy any money to tell me that, it might be true!