I use both AVG and Avast on different machines at home. Both perform very well and I'd reccomend either - which is more than I'd do for Norton. As an antivirus, Norton does a great job, but it also insinuates itself all over your computer and it is very difficult to get rid of.
The downside with Avast is that it insists on talking to you ('Virus database now updated').
Other free software that's worth looking at is Open Office. This is an MS Office contender which is less bloated but far cheaper.