I don't overkill it too much with having a huge amount of antimalware and antispyware software. I like to keep it clean and uncluttered. I mainly rely on Avast AIS and Malwarebytes Free (on demand).
http://www.filehippo.com/download_malwarebytes_anti_malware/Avast does a good job protecting against spyware and malware but others choose to do more layering of protection. Of course I am more careful than what I used to be at what sites I visit and what I download and open and I always have an image backup and file backup on hand. And I never store any passwords or account info on my computer.
Not only are others using different types of antimalware and antispyware for security but also using more secure web-browsers such as Firefox and Chrome, etc.
If you look through the forum at user signatures you can get a good idea at what is compatible. Never use two resident antivirus scanners as there will be conflicts which can be severe.
There will be other users comment with different opinions of what is good so hang in there.