NOD32 sure is the best anti-virus out there in my opinion and at least I would renew that license. I don't know anything about the rest of the ESET Security Suite, which I presume is a firewall and anti-spyware/malware software.
As far as freebie alternatives go, I'm very happy with Avast Anti-Virus and the ZoneAlarm firewall and have yet to encounter either letting a virus or intruder through. I started using Avast because at one stage it was the only anti-virus that worked on Longhorn/Vista so I've been using it for a good 5 or 6 years on at least one of my Windows installations.
If you want to do some good research into what anti-virus software to use, check out the Comparitaves page at AV-Comparatives: http://www.av-comparatives.org/
Also, PC World does periodic reviews: http://www.pcworld.com/reviews/collecti ... _2010.html
"The great majority of mankind are satisfied with appearances, as though they were realities, and are often more influenced by the things that seem than by those that are." - Niccolo Machiavelli