this is all about preferences. people have had good experiences and bad experiences with all of the name brands for security software. Norton is a good product, and the business line is Symantec. I would read reviews to compare strengths and weaknesses of each product you are considering, but i think you are fine with Norton. good luck!
I have bought kaspersky last year and since then i never had any Virus in my PC, i have 5 yrs old system (AMD Athlon 64, DDR 1 RAM) and did not see any performance issue due to Kaspersky.
Microsoft Security Essentials, period. Been using it since it was introduced and had no problems whatsoever. To put it in perspective, using it on 6 desktops, with 6 different users, 4 not very tech savvy (kind of people who aren't aware much about threats on Internet).
Kaspersky internet securty 2012..using KIS from 4 years, formatted my pc twice only, that too while upgrading to windows 7 and changed hdd. Its really a perfect security suite at best price point, firewall is damn good.