FairyTWBtW: Flight and spellcasting make this a great pick.
FirbolgVGtM: The abilities are useful, but the ability scores are all wrong.
GenasiEEPC: Not useful for Bard.
Air: No skill or ability synergy.
Earth: No skill or ability synergy.
Fire: No skill or ability synergy.
Water: No skill or ability synergy.
GithMToF: These races are powerful on their own, but not very synergistic with the Bard class.
Githyanki: All the weapon and armor proficiencies make up for the lack in a Lore Bard, giving you a solid build. However, you don’t get much in the way of ability scores.
Githzerai: Not a good fit, though it is powerful on its own.
Gnome: Gnomes don’t make very good Bards, as they don’t do much with Intelligence beyond the knowledge skills.
Deep (Svirfneblin)EEPC/SCAG: Not useful for Bards.
Forest: The Dexterity boost makes this the only viable subrace.
Rock: Nothing good for Bards.
GoblinVGtM: If you’re playing the Rogue of the group as well, this gives you a good starting point with its extra mobility and Dexterity boost.
GoliathVGtM/EEPC: Counterproductive to Bards.
Half-Elf: One of the best choices overall, given the automatic Charisma increase and customization.
Standard: Two skills is better than anything the other subraces offer.
AquaticSACG: Only in an aquatic campaign.
DrowSCAG: The spells provided are already on your list, but the extra skills are worth it.
Moon/SunSCAG: One Word: Cantrip.
WoodSCAG: Not a lot of extra synergy here.
Half-Orc: Only useful in a strength build.
Halfling: The bonus Dexterity makes this a good choice for melee focused characters.
Lightfoot: Charisma and Naturally Stealthy are a great pair of abilities.
GhostwiseSCAG: Not useful for Bard.
Stout: Inferior to Lightfoot, but not as bad as Ghostwise.
HobgoblinVGtM: Not useful for Bard.
HarengonTWBtW: All the quickness, mobility, and evasiveness you need as a support character in one tight little package.
HexbloodVRGtR: You gain several useful magic pseudo-spells including scrying, message, and two very useful spells added to your spell list with a free cast once per long rest.
Human: Versatile, and a good choice for any class.
Standard: Really the measuring stick for all the other races.
Variant: Starting with a Feat and a bonus to Charisma puts you in a good place.
KenkuVGtM: More skills, but no good ability score bonus.
KoboldVGtM: Not useful for Bard.
LizardfolkVGtM: Not useful for Bard.
OrcVGtM: Not useful for Bard.
RebornVRGtR: In most cases, this race would be mediocre. In the case of a skill-forward class like Bard, the Knowledge from a Past Life ability will come in very useful.
TabaxiVGtM: Great ability score increases and two skills.