White, blue and green cards to know

Most of white's commons are weak, but three of the top five uncommons by win rate are white. Blue and green have two standouts each.

White

• Celebrate the Mountain-king (4 mana, uncommon enchantment). When it enters, exile up to one nonland permanent an opponent controls (a creature, an Equipment or a Saga, for example) until Celebrate leaves the battlefield, and recruit. It has the highest win rate of any uncommon, 62.2%.
• The Mountain-king's Return (3 mana, uncommon Saga, 61.1% win rate). Chapter I recruits. Chapter II, on your next turn, returns a creature card with mana value 3 or less from your graveyard to the battlefield. Chapter III puts a +1/+1 counter on up to one creature.
• Stone by Sunlight (2 mana, uncommon instant, 60.3% win rate). You choose one mode. It destroys a creature with power 4 or more, or it saves one of yours (until end of turn it becomes an artifact and gains indestructible).
• Magnificent End (5 mana, common instant, 56.8% win rate). It deals 5 damage to a creature, and it costs 3 less if the target is tapped. Cast it for 2 on an attacking creature.

Chapters

White or blue

• Patient Instructor (3 mana, common creature, 2 power, vigilance, 58.3% win rate). Recruits when it enters. Its cost has a hybrid white-or-blue symbol , so it fits any white or blue deck.

Blue

• Plunder the Trollshaws (2 mana, common instant, 58.5% win rate). Draw a card. Later you can cast it again from your graveyard (flashback, 4 mana), and then it draws two, for three cards in total.
• Bilbo, Luckwearer // Burglar's Plot (2 mana, uncommon legendary creature, 1 power, 60.3% win rate). Can't be blocked. Whenever it deals combat damage to a player, draw a card, then discard a card. Its Adventure, Burglar's Plot (5 mana sorcery), exchanges control of two nonland permanents that share a card type, for example your 1/1 token for their best creature.

Green

• Mirkwood Pathmaker (3 mana, uncommon Elf, 59.6% win rate). Its power and toughness are each equal to the number of lands you control, so it's a 3/3 on turn 3, a 4/4 on turn 4, and it keeps growing. From four lands on it has enough power for ferocious.
• Quarrel (2 mana, common instant, 57.0% win rate). Your creature deals damage equal to its power to their creature, and theirs doesn't hit back. It's green's best common removal, as long as you have a big enough creature.

Power/toughness