First its wrong to lable everthing as a virus.
No AV has a 100% detection rate.
Norton a good AV however its known to miss on some forms malware, therefore people run malwarebytes along side Norton.
Spybot - an antispyware program, not an antivirus program therefore it does not remove viruses, in its day Spybot was one of the best, however nowadays its old school, superantispyware is better.
Would i pay money for an antivirus program ? no, you are more like to get malware nowadays than a virus.
I think you need to do more research, so that you understand what a virus is & what is not a virus.
Kaspersky, Avast, Nod32 are all good AVs but not one of them can give you 100% protection.
I run only free programs & I cannot remember the last time I got a virus, malware or spyware.
Edit:
About your Additional Details:
If you have been attacked by viruses a lot you must be going to unsafe sites or your PC has security vulnerabilities, the fact Norton block them shows Norton is doing its job, however no AV can protect you if you go to unsafe sites or your PC has security vulnerabilities - check to see if you have security vulnerabilities:
http://www.bleepingcomputer.com/tutorials/detect-vulnerable-programs-with-secunia-psi/
I run free Avira on XP OS & Free MSE on Vista OS, both work very good, to remove spyware I use free superantispyware, to remove malware I use free malwarebytes, to find out if a sites safe, I use free WOT, if I'm going to an unsafe site I use a sandbox web browser (sandboxie free), to cut down on spyware I block third party cookies & use free do not track plus, I use free window firewall on both my PCs.
As I said I don't have the problems your have & my protection is free.