I suggest my setup:
- Mozilla Firefox
- Mozilla Thunderbird
- Zone Alarm Security Suite (Everything you need. So powerful... When sat up really precisely, you got real control of your internet.)
- NO P2P !!!!!! (We'll never say it enough, P2P's are killing machines. If you want downloaded music, go on IRC, like Undernet there is tons of Warez Bots to download songs. No bull**** and it's all music, movies, sometimes games and porno movies... NO VIRUSES IF YOU USE YOUR HEAD !!!)
- Virus/Spyware Scan every Thursday during WWE Smackdown!

- Format every christmas
Also, people, try to stay away from porn websites, they carry viruses and spywares too.
EDIT: Oh forgot, disks cleaning from useless programs and files once a month. Keep your trashes at the dump, not in your pc.