1. anti-virus software: AVG (http://www.grisoft.com/ for free version http://free.grisoft.com) or Avast (http://www.avast.com)
2. anti-hacker software: I don't know, never used any, never need any
3. anti-abuse software: Don't know either (is there any software categorized as anti abuse?)
4. anti-spammer software: Well, why would you need it? Spam is handled by mail server not you.
5. firewall? Zone Alarm (http://download.zonelabs.com/)
6. anti-trojan and worm software: most antivirus product also include antitrojan and antiworm software so : AVG

They are all free or have a good and functional free version that often best competitor's paid product.