I think what I am ultimately going to do is keep Norton 360 on my newer PC that runs windows 7 until my subscription runs out, as long as Norton does not present any serious issues to it. I also have Malwarebytes free edition installed (I looked at Malwarebytes Pro and it seemed like very little extra comes with the upgrade.) I also plan to install super anti-spyware and run that from time to time. I also use a program called SlimCleaner, which is mainly for getting rid of cookies and other junk, but many people say that by removing this stuff SlimCleaner actually also deletes spyware. And if you look through the menus that the SlimCleaner software displays, the options are very vast and I have been pretty impressed with it.
Finally, when Norton expires, I will go with either MSE or Avast, probably Avast only because I have used it before and can first hand say that it really worked great, although that was with the Vista OS, but it is so similar to Win 7, I think it will work fine. I will of course, still be running Malwarebytes, Super Anti-Spyware, and SlimCleaner. I also was thinking about Spy Bot - Search & Destroy. I used it many years ago when I still had XP, but recently I have read mixed reviews on its competence.
As for my old PC that runs Vista, I think I will try MSE, since the free Avast registration expired and Norton 360 has been real trouble for it, (Avast free edition is a bit misleading I think considering it's only is free for a year) as long as MSE works on the Vista OS. I will of course still be running the other 3 programs I mentioned earlier on it.
I appreciate everyone that chimed in, and if anyone else has any suggestions or comments, I welcome them.