My top anti-malware from experience in home users and corporate environments has got to be Malwarebytes Anti-Malware. They also offer an additional product called Anti-Exploit which both have free and paid versions. They are an extremely good combination and are light on resources. This can be run in conjunction with Windows Defender without issue.
System cleaning is a little more complicated, but CCleaner when properly configured is really good at cleaning out the junk from the system.
Other measures is stuff such as enabling User Account Control (UAC - that warning that pops up whenever you try to run a program as admin) which ensures nothing runs with admin privileges sneakily.
In terms of security, the most important thing in my opinion (speaking as a security specialist) is keep software up to date, especially Flash/Java. If possible, remove Flash and Java simply because a new exploit comes out for them every couple of days. Another obvious one is don't click on links in emails unless you were expecting the email.
As the browser is one of the most common drive-by exploitation points, it is important you don't install junk add-ons to it. Chrome is more secure, but Firefox is more private (ie doesn't send Google your info, tradeoff is your choice). Two extensions I strongly recommend are
HTTPS Everywhere and uBlock Origin (like AdBlock Plus, but blocks malware as well as ads and takes less system resources).
Regarding passwords, I recommend a good password manager. Note the word
good. The built in one to chrome and firefox are awful for security, do not ever use them. Instead, use something such as LastPass which is my one of choice, and another is KeePassX which is for Linux systems. LastPass has 2 factor authentication to prevent malicious logins even if you are being keylogged, which is very good. Using unique passwords, at least 16 characters for each login is also a top measure, which LastPass comes in very handy for.
I could go on all day.... but you get the idea.
