I wanted to comment on the use of MAC for Macintosh. I would say be carefull with the use of all caps MAC, because that could lead to the thought that you are talking about MAC address, cause it is offten only refered to as only MAC. Not a huge deal, just wanted to point that out.
I would dissagree with throwing out the debate about what is best. I have seen, unconfirmed I will add, talks about the Symantec Antivirus source code being put out on the web. This could lead to helping to write viruses that can bypass the scan engine. Something like that should allways be looked at as a potental threat and taken in to consideration when chooseing a security software. Granted it is older software, but is still in use.
I do agree with you 1024% that, not a single computer should be on the web with out some sort of protection, AV and maleware. That is a very important thing to do when running a computer. My Intro to computers teacher told us one time that, the only computer not at risk is one with only a processor, memory and a rewriteable storage device (ie HHD, SSD, Flash Memory, NVRAM). Though you wont be able to do much without an OS, software, network adapter, keyboard/mouse, so forth and such on. If your computer has more thatn the three basic things needed to be called a computer, then you are at risk. That is a great idea to live by.
On the flip side thought there is such a thing as too much. You never want to put three AV softwares running on the same computer. That could cause a conflict between the three and lead to one trying to protect you from the others.