I personally do not use much for Windows OSs (just at work) but as I work as a tech guy (who knows what my proper job title is) who must fix them, I know that one is not enough. It is also no contest - I have seen personally at least 12,000 in AdAware to that persons 4000, like anyone cares - as it counts every single cookie belonging to their blacklisted sites as a seperate "attack" or what have you. Also, how people can have these break their systems instead of fixing them is beyond me.
I personally do not like the "Spyware" word craze Gibson started as not all of this software actively "spies;" that term is rather vague - and even those that do have different levels. But, seeing as a lone person cannot quite change peoples minds, it stays... Anything-ware is overused, ..might as well use it again for marketing malware ;p
Also, just another thing - if you consider Virtual PC so great, ...*sigh* :/ ..but that is left to another debate...
I always use classes for generic things, like stuff per forum post on this site and IDs for pretty much all single things like, say, the logo. When things look similiar but should be seperate things, I seperate the CSS for the items into common parts, i.e.