This decklist is currently the most common build of Jeskai Yorion Lukka, which is considered the best deck in Standard.
Sorento04 played this specific decklist to a 5-0 finish in the MTGO League on May 21st, 2020.

Companion
1
Yorion, Sky Nomad
Planeswalkers (12)
4
Narset, Parter of Veils
4
Teferi, Time Raveler
4
Lukka, Coppercoat Outcast
Creatures (3)
3
Agent of Treachery
Spells (4)
1
Aether Gust
3
Shatter the Sky
Artifacts (1)
1
Glass Casket
Enchantments (24)
4
Omen of the Sea
4
The Birth of Meletis
4
Omen of the Sun
4
Fires of Invention
4
Elspeth Conquers Death
4
Shark Typhoon
Lands (36)
3
Castle Ardenvale
2
Castle Vantress
3
Fabled Passage
4
Hallowed Fountain
4
Island
1
Mountain
4
Plains
4
Raugrin Triome
4
Sacred Foundry
4
Steam Vents
3
Temple of Epiphany
Cards (80)
Sideboard (15)
1
Aether Gust
3
Dovin's Veto
1
Glass Casket
2
Deafening Clarion
3
Mystical Dispute
2
The Wanderer
1
Yorion, Sky Nomad
2
Dream Trawler
More Standard
This is the first part of a big update of our decklist section. You can expect more current Standard decks here, as well as Standard Tierliest article coming later this week.