Is norton the full package?

i have always had norton security but also installed

 

spywareblaster     [free ver]

superantispyware [free ver]

Malawarebytes     [free ver]

 

is there any need to have these 3 or will they just duplicate what norton security 2011 does.

 

does anyone else install any other security software in addition to nortoin security? not sure if i have been over the top or not.