NOTE: If your looking for recommendations on free antivirus, check this question: http://superuser.com/questions/2/free-antivirus-solutions-for-windows

Much like the above, I'm curious to opinions on the best PAID antivirus solution, personal or commercial.

Enterprise solutions are welcome and as much detail regarding costs is welcome.

Personally I'm looking for a licence that will grant me more than 1 computer install and quality technical support, for personal use.

as in the free antivirus question:

See if your antivirus of choice is already listed. Chances are it is.

If you spot an answer that mentions one you already use, vote that up if you think it's a good solution.

If you know of a feature or drawback not listed, or can include experiences in dealing with it, please edit the answer accordingly.

If you know of any that can also be used at work please point this out.

This covers all Windows platforms from XP, Vista and Windows 7. If you see an existing entry that needs an update or to add your testimonial, please do.