I had to get this "removal" tool from some computer repair guy to get the trial version of Norton off.
At least Trend Micro was descent enough to have a built in removal tool to get rid of it's trial.
I would recommend
Vipre simply because it is very thorough but it uses a very minimal amount of CPU. The only thing is, you have to completely (sometimes by hand) remove
any trace of other antiviruses or your computer will crash upon restart.
Review It didn't get as high of a review as Avast though, but the fact it has an unlimited home license and on average .17% CPU usage (vs .30% for Norton) it's worth at least looking into.
I'm trying not to sound like a salesman.
Oh, and I'm pretty sure that Best Buy won't carry it. But with the way they handle computers, that's a good thing.