Im using kaspersky Internet secuirty it's pretty good. I also tried eset but didn't like it to much because of the lack of options. I don't like norton to much and mcAfee mainly because if you get a certain virus it ruins the structure of the anti virus or something that makes you have to unistall it. Sometimes not even the uninstall will even work and you'll have to format your hardrive to get it out in my experience. Haven't had any problems with kaspersky or eset. your best bet with an old laptop is probably eset due to its speed.

+1 for KIS 2010

I use KIS 2010 on one and ESET Smart Security on teh other, both are pretty good, though KIS is a bit more complex

i think Norton

Kaspersky Internet Security 2010

For me, is the best! I recommend!