do you need them to be free ones? if so, AVG or Avast as suggested are good. for pay ones, i have always used McAfee with the windows firewall. are you using windows? xp, vista? linux? apple? if vista, it has a two way firewall, if xp has just incoming firewall. maybe zone alarm for two way free firewall. Norton is good too, but may use more system resourses from what i've heard....although probably not much more than mcafee does.