Disc/Rogue. 'Nuff Said.
Please don't run Shadow/Rogue, it makes me sad.
As for strategies, Arena Junkies is actually a really good source of information if you have the time, the comp I mentioned focuses on just CCing one person into oblivion with Sap, Blind, Fear, etc.
I rolled Restodrood/rogue. It wasn't easy but it worked. I suggest it for people who like really long fights. Like really long. We capped the system once, 47 min game, both teams lost 12 points, it was a draw.