It looks to me like the polling list covers only Antivirus & Internet Suites. However the topic of this thread does not limit votes to just those categories. Therefore, I voted "Other", denoting Private Firewall. The support provided by the proponents of PFW is the fastest, most friendly, most competent that I have ever encountered.
Microsoft never failed to answer my questions, through its many official channels. So, my vote goes to Microsoft.
Of the products I have used... as much as I hated to give the vote to Norton I had to because they do follow up on the issues I have contacted them on, even if I didn't agree with the solution. ESET isn't bad but it seems that if a problem doesn't have an immediate solution that they stop replying to the threads posted. That said they do try harder than most. Kaspersky support seems angry and bothered by anybody reporting issues. I try to avoid them.
Another vote for Ilya (Defensewall) Support is top notch and second to none. (I believe tzuk w/Sandboxie would be a close second)
Tzuk is brilliant and Ilya (if he agrees with you ) provide exeptional support. Of the bigger companies Emsisoft have always been very responsive for me. I have to say my one and only experience with Norton for a relative saw a 3 month trial NIS converted to a year long trial. I appreciate from years hanging around here that is not always the case but you can't get better than that. Cheers