Hmm. I know you asked about spyware, but I never get any spyware, so I'll just list the whole shebang, since there's not a lot of it anyway.

I have
ZoneAlarm for a firewall. The free version... since I have dial-up, it's more for curiousity than anything. If/when I ever get cable or something like that, I may spring for the Pro version.
For virus protection, I use an "indie" sort of program called
NOD32. It has great virus detection, and has the same sort of features as McAfee or Norton... it's just a heck of a lot smaller in disk space and RAM/resource usage, and IMHO is easier to keep updated. (Costs about the same, too.)
I use an
ad-blocking HOSTS file to, well, block ads.

For my browser I use Opera. I tend to surf with plug-ins and Java turned off, unless I come across a page that really needs it. Then I can just flick them on with a couple button presses. Whee! I keep javascript enabled (because that's ubiquitous enough to be worth leaving on), but I have Opera set to "Open requested pop-ups only".
I use Opera's cookie manager to only let through the cookies I need for my forums and other sign-in thingys, and have it block everything else. Opera allows you to turn off referrer logging, but I do not for the fact that you need it enabled to be able to get past many servers' hotlinking prevention scripts. Such is life.
I don't really keep up with Windows updates much, to be honest. I seldom have any errors, and most of the security stuff has to do with Internet Explorer and Outlook (Express) anyway... and I've uninstalled both IE and Outlook with a program called
98Lite. (Great program... makes almost everything in Windows installable/uninstallable, so you can get your Windows setup nice and clean. I very rarely have the BSOD show up anymore. There's a version available for Win XP, too!)
Finally, as I said, I never get spyware. Opera doesn't run Active X and never automatically installs stuff, and I always research a bit whenever I want to download a new utility to make sure it doesn't have any spyware in it.
(I personally feel adware in and of itself isn't necessarily a bad thing... it's basically just a program that displays ads. It's when the program bases those ads off keeping track of your surfing history and other stuff you didn't volunteer that it's an issue, IMHO.)
Peace & Luv, Liz