Although I'm a total death eater fan, i'm all for sirius

Severus was Voldemort's and Dumbledore's right hand man.

As much as i love sirius and snape equally, i think it be one of those fights thats brutual, messy and even fight, ok alot of cheating on both sides but an awesome duel!

... I can't choose! Umm... I'm getting a bit of a Sirius vibe, he'd probably use his animagus powers to cheat.

It'd be a really good duel though!