FairyTWBtW: Flight and some supplemental spellcasting
FirbolgVGtM: Bonus Wisdom and some minor spellcasting.
GenasiEEPC: The bonus to constitution is a welcome addition to the Monk’s abilities.
Air: Dexterity increase goes a long way to aid your combat abilities.
Earth: Poor choice for Monk.
Fire: Poor choice for Monk.
Water: Wisdom increase and Fire resistance.
GithMToF: The base Gith package isn’t stellar for Monks.
Githyanki: A poor choice for Monks.
Githzerai: A Wisdom increase and a few peripheral abilities that are surpassed by other races.
Gnome: Gnomes don’t have any traits that benefit Monks.
Deep (Svirfneblin)EEPC/SCAG: Poor choice for Monk.
Forest: A Dexterity increase, but otherwise a poor choice for Monk.
Rock: Poor choice for Monk.
GoblinVGtM: Between the ability score increases and the Nimble Escape option, you have a ton of bonus action options that would otherwise cost you a Ki point. Fury of the Small is a nice addition to your already prolific attack suite.
GoliathVGtM/EEPC: Entirely Strength-based. A poor choice.
Half-Elf: Monk is the one class Half-Elf isn’t a stellar choice for, given its many small bonuses. A Monk needs a single strong support suite of abilities from its race.
Standard: A mediocre choice. Monks are already set on the few skills they actually need.
AquaticSACG: Only worthwhile in an aquatic campaign.
DrowSCAG: Full Drow is better suited for you if you want the spellcasting.
Moon/SunSCAG: Nothing good for Monks.
WoodSCAG: Just be a full Wood Elf.
Half-Orc: Poor choice for Monks.
Halfling: Luck compliments your many attacks rather well. And a Dexterity increase to boot!
Lightfoot: Charisma isn’t important for Monks. The Stealth proficiency might come in handy.
GhostwiseSCAG: Perfect ability score increases, but not much else.
Stout: Constitution increase and extra hit points.
HarengonTWBtW: Quick reflexes and extra speed are a hat-on-a-hat for a Monk, but when you’re trying to min/max this is a good option.
HexbloodVRGtR: Nothing that is very useful for Monks.
HobgoblinVGtM: A tempting choice, given the Constitution increase and Saving Face ability, but overall less useful than many other races.
Human: Humans are a solid choice for every class.
Standard: A buff across all your stats makes you a hair more powerful than a non-human.
Variant: A feat at first level, and a bonus to your two main stats gives you a great edge at first level.