Grim Guzzler - Mage with all the freeze cards, big taunts, Mirror Image, Annoy-o-tron, and general fatties. Got it first try, 2 Frost Novas + hit face with all the summoned big creatures
Dark Iron Arena - I used the same Mage stall deck with some bias towards early game, Kirin-Tor Mage + Mirror Entity. I reset until the bot got Lorewalker Cho and I got Mirror Image. I manipulated the bot into playing Mirror Image a lot, while trying to get him to have 0 attack on board so I could win off fatigue. I didn't get all the way to 0, but I did get
to 5 mirror taunts, Cho, and a 1/1. Unfortunately the bot drew Flame Leviathan...but luckily the bot still played Mirror Image, so I had some time. I had enough freeze from Lorewalker Cho to stall until I drew Blizzard, then killed him over 2 turns by Blizzarding away all the taunts.
Emperor - A standard Priest deck, lots of healing and a few gimmicks. Got it first try with Priest - Power Word Shield on Wife turn 1, Lightwell turn 2, Inner Fire turn 3. Lightwell and Northshire Cleric drew me enough draw to keep going, a Cabal let me steal an Axe Flinger, and the AI never had an answer to my Lightwell so I hit for 5 every turn.