Anti-virus recommendations

[anarky]

What do y'all on Windows use for anti-virus? I've had McAfee for a few years and never had a problem (it came with the computer, and I just kept it on without doing as much research as I should've). Or so I thought. I've been looking more closely at the resources now that I've rejuvenated the Dell, and noticed that McAfee's real-time scanning totally maxes out the CPU, even when it's at 5-10% from all other processes. Needless to say, this ties up an otherwise quick computer. (It's probably been going on for a while, and I assumed it was something else tying up the system.)

And, looking at reviews, it appears it's not quite as good at blocking and removing viruses as I'd assumed. I also rooted through their forums when I had installation and validation issues (three fucking times), and noted their representatives are, well, assholes.

I've noticed several sites and people recommending Microsoft Security Essentials, which is free, as well as supposedly better at managing resources and about the same with blocking malware as McAfee. Should it be run in conjunction with MalwareBytes and/or Spybot Search & Destroy?

I'm debating whether to continue the McAfee subscription to the end, or just uninstall it and be out the money for the rest of the year (they don't pro-rate cancellations). I don't think I need additional little tools to give me a green checkbox to let me know YouTube is safe.

[Ran]

I use the free version of Avast. It is on cnet's website.

[Diabolical]

I have Avast also.
Everything else I've tried slows my antique down even more, although I've never tried MS SE.