Personally I find McAfee a bit slow, I would go for ESET smart security or Kasperksy (which you can get free if you know anyone who uses internet banking with Barclays).
MSE it is free and does everything Norton does and as Which says it is second only to Bullguard and way above McAfee and Kaperski.
Just be sure you have fully removed and disinstalled Norton before you install MSE or the 2 will 'fight' each other. Why pay for what you can get free ?
Don't pay, they only difference is support which for a home user isn't really required. You also need to use 2 separate programs to ensure all bases are covered. I used AVG and Sophos...both free.