Snape as Snape isn’t “hot,” really, to me; he’s incredibly intriguing and captivating, at least before he becomes a bit of a woobie in the last novel. I really wish JKR hadn’t made him all about the Lily wuv. Spare me.
Rickman as Snape? Hella hot. He does sooo much with a withering glance and the sonorous intonation of acidic insults.
But then again, Rickman as pretty much anyone is hella hot. He made me root and lust for Judge freakin’ Turpin.
But I don’t see him as Sirius at all. Sirius (post-Azkaban imprisonment) is hyperactive, immature, and overemotional. I can’t picture Rickman in such a role. He could probably play it, because he’s a very good actor, but the role doesn’t suit his forte, which is playing intellectual, collected, [del]smouldering cauldrons of lust[/del], repressed, and witty (or acidic, depending on the character’s temperament).
It’s funny someone mentioned Malkovich, because I love them both in the same role – Valmont, in Les Liaisons Dangereuses. The first time I “discovered” Rickman’s awesomeness was during a broadcast of the Tony Awards in the '80s, when Liaisons was nominated and Rickman performed a scene as Valmont opposite Lindsay Duncan’s Marteuil. (Ah! God bless Youtube. Fast foward a bit to get to the good stuff.). He spoke two words that forever won me over: “Take. Care.” Oh my God, what that man can do with his voice!
And Colonel Brandon… “Give me an occupation, Miss Dashwood, or I shall run mad.” “The air is full of spices.” “For there is nothing lost, that may be found … if sought…” MERCY!
PS and by the way, the answer to “who has the best voice?” is Rickman and one Patrick Stewart. Come on.