Just like in the recent past, Blizzard is once more running a Choose Your Champion event, but this time is for the Hearthstone [Free] Championship Tour Winter Championship. The way this works is you pick one of the sixteen players competing, and you get a free Gadgetzan card pack every time they progress in the tournament. If the player you pick manages to go all the way, you'll get four free packs, but even if he loses from the first round, you'll still get one free pack. Last time this event happened, a large majority of players voted for Thijs, but he promptly lost in the first round.
The competitors are a mix of familiar and unfamiliar names, but there's no bonus for picking underdogs, unfortunately. You have until March 21st to pick a player, and once you pick, you can't change it. So, pick wisely. Go here to lock in your vote.