Spyware
Note: It is fine, & recommended, to have more than one spyware scanner on your computer, however, a lot are now offering resident protection.  Too much resident protection will slow your computer down and have detrimental effects.  It is recommended you set up the software so that only one has resident protection running.
4/5 4/5 4/5 4/5 4/5
Spybot S&D
Description:
Scans and removes spyware and adware from your computer.

Pros:
Easy to use with a good interface.  Supplies resident protection in the form of an add-on called TeaTimer.
Configures Internet Explorer and Opera to block known nasties before they reach your computer.

Cons:
Does not automatically update.

Price:  Free for personal use.

Verdict:  4/5  Download it now!
4/5 4/5 4/5 4/5 4/5
Ad-aware
Description:
Scans and removes adware and spyware.

Pros:
Easy to use.  Also scans for negligable risk entries, which are temporary files that could contain personal data.

Cons:
Does not automatically update.  No resident protection on free version.

Price:  Free for personal home use.

Verdict:  4/5  Great.
5/5 5/5 5/5 5/5 5/5
Spware Blaster
Description:
Protects against spyware by configuring Internet Explorer or Firefox to block know nasties before they get to your computer.  Intended to be used with a spyware sacnner.

Pros:
Small app that doesn't need to be running to protect you, so you can have some resident protection running at the same time without fear of slowing your computer.

Cons:
Automatic updates only available on paid-for version.
Not compatable with Opera.

Price: Free for perosnal use.

Verdict:  5/5  A "must have" addition to security.
Firewall
Additional Security
Note: While most spyware protection software is genuine, there are a couple of products that are not, and actually install spyware on your PC.  Go to spywarewarrior for more info on these "rogues".
Hosted by www.Geocities.ws

1