norton is bloatware and it hogs hell lot of your systems resources. the norton firewall is also buggy. i suggest u keep away from norton or just use the norton antivirus 2005 n nuthing else. it has a good detection rate.

for firewall zonealarm is the best.

i dont think avast is a very good solution though the best part it is freeware. you cannot get any real good freeware a/v . though avg,avast etc are decent. for paid a/v go for kaspersky.

for spyware the more you have the better ... ms antispyware is good and so is spybot.

also dont forget to get adaware for adware.
all these combined shud offer pretty good protection. and remember dont install n number of programs to keep your comp safe. it will only make a mess and your comp will become real slow. go for 1 from each category i.e a/v,firewall.adware.spyware.

and one final advice wait for swatkat to reply to your topic and pay HEED to his advice as he is a brainiac in these kinda matters.