Here is the full list of all 18 Poker Night 2 achievements. It takes around 12-15 hours to unlock all of the achievements on Windows.
Activate the Portal deck, felt, and chips simultaneously.
Win GLaDOS's bounty item.
Unlock all decks, felts, and chips.
Win Claptrap's bounty item.
Activate the Army of Darkness deck, felt, and chips simultaneously.
Win Brock's bounty item.
Win Sam's bounty item.
Activate the Venture Brothers deck, felt, and chips simultaneously.
Activate the Sam & Max deck, felt, and chips simultaneously.
Purchase a drink.
Win Ash's bounty item.
Activate the Borderlands deck, felt, and chips simultaneously.
Purchase a set of chips.
Purchase a felt.
Purchase a deck.
Win a tournament.
Win a hand.
Achieve a lifetime balance of one million dollars.