I'm not a fan of Norton. Once you get it installed you play hell getting rid of it if you decide not to renew with them. On my Dell machines I just have "Avast" anti-virus running. It is free and good.
I think I pay around $60 a year for Mozy - and there is no limit to how much I can store with them. It is the same with Carbonite. The initial upload can be annoying since it is starting from scratch and can take a long time (days or weeks), but once that is done then all it does it update any new or revised files each night.