http://search.pricewatch.com/search?q=kaspersky+internet+security
guys, kasp is cheap, its worth it, MORE than worth it
as for firewall, if you dont use whats with kaspersky, outpost is the best (read, hardest for me to bypass)
superantispyware is a good combo with malwarebytes if you dont trust that you got everything if your removing an infection
ps whilst nod32 does use less resources, its heuristics are CRAP compared to kasp's (sorry clix, they are), its pretty easy for me to get around personally, kaspersky also lets you update to the latest version as soon as its out, no cost, your license lasts for 12months, all you have to do is enter your license in the new version and it all just works
oh and yes, windows updates are a must, as well as keeping acrobat upto date as well, also i highly recommend NOT using internet explorer. firefox or opera, see what you like, ie is reknown for security exploits, yes ff and opera get them too but they are FAR less targetted than the generic ie exploits
edit: clix you should lock and stickie this thread in its current state, we get this question a fair bit and we always answer the same way, this 1 hasnt turned into a flame war yet so it'd be a good 1 to get stickie... just my 2c