The first deck I wanted to try for day 1 is the Pure Paladin
I played it in the top 100 EU with a good win rate 66% (against the hunter it's a win but the decktracker didn't register it https://hsreplay.net/replay/BW96VL7iQRfiMZbdLErxoU)
This card is OP and does not need my comment.
21/11: The meta has changed compared to the first days and it's time to update the list.
Before there were a lot of deck Control with the old gods. There are now plenty of aggro (like Aggro DH) or mid range (like Evolve Shaman) decks. These decks don't give you time to corrupt Carousel Gryphon, but playing a taunt on turn 5 or 4 can make a difference; for this I changed Carousel Gryphon to Devout Pupil. Now you no longer need to have cards to corrupt Carousel Gryphon so I changed Lightforged Crusader for Argent Braggart.
win rate with latest version:
What to keep at Mulligan with stats from HSReplay:
CrimsonpandaHS video guide: