Free Malware and Virus Scan
Malwarebytes - Powerful, free malware removal tool
Adware- Adware removal tool
IObit- Malware Fighter
Microsoft Security Essentials- Microsoft's antivirus solution
Online Scans
Bandwidth Testing and Calculators
Browsers
Firefox - A great, open-source web browser.
Chrome - Google's fast, easy to use web browser.
Internet Explorer - I guess, if you REALLY have to, but even then...
Misc Tools
MXToolbox- list MX records for a domain in priority order.