I have dealt with the 2 big ones.... Norton and Mcafee. Of the 2, McAfee is the better choice. At least when the update period has expired and you wnat to uninstall it, it actually does uninstall, but Norton just starts an uninstaller, and claims that there was a problem and has to close. has happened like that on every machine with Norton that I can remember.
NOD32 isn't without it's flaws and incompatibilities, and frankly it scares me that an AV program can cut the scanning times down by half when all other variables are the same and equal. If I lose my keys, I can cut down on looking time by simply poking my head in each room and saying they aren't there, but I won't find my keys that way, either. Also, I don't really like how half of the files it scans are locked, and it reports that it cannot scan the folder. The other problem I had with NOD32 was the way it could not run with the nVidia firewall. I didn't try it with any other firewalls, but I am on dial-up, so a firewall isn't quite as important as it is on an always-on connection.
But, so far, other than those few minor flaws, I kinda like the program. It's extremely small, not a resource hog, and it's about 1/3 of the price of the "big ones".
My old sig didn't match the new board. Therefore, you get to read this text sig.