If you want an all around internet security suite and firewall, I've been highly pleased with Trend Micro's PC-cillin. It doesn't seem to slow my computer down like Norton did, and it has received good reviews from the computer magazines I checked.
Have used Trend Micro for years but their latest update download sucks. Purchased it and downloaded. It never would install. Haven't gotten my money back from they yet either. Use to recommend Trend Micro but not anymore.