The January 2012 edition of Which Magazine has a survey on Security programs both paid for and free in which Microsoft Security Essentials (free) comes out as the second best program with an 84 per cent score, just 2 per cent below the paid for Bullgard Internet Security 12 which achieved 86 per cent. BitDefender 2012 came last out of 18.
Strangely, I was browsing a bookshelf in Sainsburys whilst my wife and I were shopping the other day and I came across a computer magazine doing a similar exercise in which BitDefender came out top and Microsoft Security Essentials came out poorly.