I like Avira - plus I do occasional scans with Spybot or Malwarebytes. In addition I connect through Sandboxie. Makes me feel a whole lot safer! http://www.sandboxie.com/
Just a word of warning - do not rely on MSE. I used Avast for years until a computer specialist told me about MSE and how good it is. Uninstalled Avast and got MSE. Result: Trojan Ramnit. I have tried everything to no avail and tomorrow another friend who works in IT is trying to fix it.