If you're looking for a retail version of antivirus and firewall, Norton all the way... However, there are much better things that are free, like ahajv4life said. My personal favorite for antivirus is AntiVir, it's free for personal use, but not for corporations and such... For a firewall, I'd have to agree on Sygate Firewall...
They're both very similar, both hog resources, but do a reasonable job. I prefer a dedicated Anti-virus\firewall combo. For paid AV, Kaspersky is probably the best, there's no need to pay for a firewall. Or, as mentioned above, get both free. There's 3 of each to choose from here.
Oh yea norton is the best Antivirus software in the world. Version 2004 it slew down my computer but version 2005 it's really fast and It's just like set it and forget it, and it updates by itself. But McAfee takes so much system resources so yea Norton is the best to go with.
Almost forgot, norton 2005 also has Internet Worm Protection so it's a firewall also, you don't even have to install Norton Internet Security once you install norton 2005.
I have McAffee and it is AWFUL. We have Norton on our other computer, which, after like 4 years has probably gotten ONE virus. On our McAffee computer, somebody has hacked in and is changing our homepage to a *not good* page and adding *not good* links into our favorites. I would DEFINITELY go with Norton!
For the crowd who have lower end computers (this includes me) should'nt really pick a solution from Symantec, actually noone performance concerned should.
However if your in need of a free yet great anti-virus solution I recommend you to checkout AVG from Grisoft. You don't have to pay a dime to recive a sufficient anti-virus protection with an high detection rate considering it's free.
I had Norton for a long time and it was great but sometimes it would uninstall itself or lose files. But AVG is the BEST anti-virus and it's free. But when it comes to Norton vs. Mcaffee, Norton wins hands down.
Even if I had to pay for it (which I have for the computer at the office) I'd get AVG. I just haven't found an antivirus program as efficient as this one. We kept having stability and performance problems with my daughters computer (you know kids will download about anything once or twice), so I downloaded AVG-Free on her computer, which had Norton 2005, and it found 20 something files that Norton never saw. AND I AIN'T pullin' yo leg. She is not having anymore problems now.
Trend-Micro is what our software vendor uses... they rave about it and it's reasonbly priced. On the cost side it's a little higher than AVG Pro. AVG Pro is only $39 for a 2-YR sub.
The biggest thing I don't like about Norton is it being a resource hog... unless you are using 2002... it's not quite as bad. And of course the fact it didn't catch the trojan horse infections that AVG found in my daughters computer.