Hi Folks. I'm running Vista 64 bit Sp1 and I think it is absolutely superb. I'm using Kaspersky Security Suite 7 which costs about 30 GBP. As I still have a few months to run on my licence I've been able to upgrade to verion 8 for nothing.
I think that Vista 64 is naturally more secure then XP but I can't fault Kaspersky. I still have Spybot S&D and Adaware and I run them every couple of weeks. They rarely find anything and when they do it is something that is not much of a threat.
I also use CCleaner, Auslogics defrag and Ashampoo Winoptmimizer and am pleased with the result.
Maybe this is overkill but my system runs like a rocket and I've not had any problems that weren't my own fault for almost a year now so I would definitely recommend Kaspersky. I know it's not free but it's cheaper than some competitors and works great.

Cheers to you all, John