Norton, it's treated me well so far, although I have heard of others not having such a good experience with it... Well that and I have McAfee site adviser and I use NoScript on websites I don't trust fully...
That it it has such a quaint and fun to say name!
How I imagine it:
"Alright Norton, time for our daily virus check buddy!"
"...We had one 5 hours ago, and you didn't do anything between then and now besides look at Youtube videos..."
"Shut up! I can be paranoid if I want!"
...God I'm lonely.