Do I have to answer? Isn't it common knowledge now?
Rickman Snape, 100%. When Rickman was cast as Snape, I had to see the movies. The movies led me to the books. I'm a Rickman fan first, Potter fan second. Damn Die Hard movie...
In my head, Canon Snape and Fanon Snape are portrayed by Alan, body and voice, no matter the characterization. I can't separate them. Like Madapple and NightScribe, I don't want to.