I have tried just about all the best-rated AVs, and I'm currently using ESET Nod32 5.0, which is a prerelease Beta, cloud-based trial version. It is very good, and the final release should be available for purchase within two months. Test results for ESET Nod32 4.0:http://www.eset.com/us/home/compare-eset-to-competition
I am looking forward to the final, stable release of Version 5.0. It will be the first cloud-based AV for ESET, and it already has proved very effective on my computer, especially the email protection it provides. As with Panda Cloud, which I had installed previously and is also very good, ESET Nod32 5.0, works very well alongside Microsoft Security Essentials. There are no conflicts whatsoever. Now, Microsoft is not going to tell you that because they do not want to advertise for any other company. I just know that from my own experience.