I'm with davico_rosello here. I found the original post that Holmes4's link references to. The antiviruses were not tested on a mini. I didn't test these antiviruses on how secure they are. I tested these for performance alone. I think the top priority should be to have some protection, but have minimal impact on performance.
Also, what some people are posting here is exactly what I wanted to avoid. We have enough people at MyDellMini telling us what they use, and that their product is great. I wanted to put a stop to this.
My result is this: If you're looking for protection with little to no performance hit, use NOD32. If you like another product, fine. You don't have to shout out to the world.
NOD32 is not a bad antivirus. I think that it will be perfectly fine for a normal person. If you are constantly download "leaked next-gen video games" from torrents, it might not be right. Practically every AV I tested would be fine. NOD32 won because it harmed performance the least.
I will continue testing next weekend. I might try AVG and Avira and maybe a retest of Norton.