OK, here's my collection:
A: Accelgor, Alakazam, Alomomola, Altaria, Audino, Axew, Azelf, Azurill
B: Beedrill, Blastoise, Blaziken, Buneary
C: Carkol, Cinccino, Conkeldurr, Crobat, Crustle
D: Deerling (autumn), Delcatty, Delibird, Dhelmise, Diancie Dragonite, Dratini, Drifloon, Ducklett, Dusknoir(x2), Duskull, Dustox
E: Eelektrik, Electivire, Eldegoss, Exeggcute
F: Farfetch'd, Flareon, Foongus, Froslass
G: Gardevoir, Grovyle
H: Herdier, Hoppip, Hydreigon, Hypno
J: Jolteon, Jynx
K: Karrablast(x2) Kecleon. Kirlia, Krokorok
L: Landorus, Larvitar, Leafeon, Lillipup, Lopunny, Loudred, Lumineon, Luxio, Luxray,
M: Magnezone, Makuhita, Manectric, Mamoswine, Marill, Marshtomp, Mawile, Meowstic(female), Metang, Metapod, Misdreavus, Moltres (Galarian), Munna
N: Nidoking
P: Pachirisu, Petilil, Pidgeotto, Pignite (x2), Pikachu, Piloswine, Pineco, Plusle, Poliwag, Porygon2, Probopass
R: Regigigas, Regirock, Reshiram, Roselia, Rufflet
S: Salamence, Sceptile, Scolipede, Sentret, Seviper, Shellos (east), Simisage, Slowbro, Smeargle, Sneasel, Snivy, Solosis, Spoink, Spritzee, Stunfisk, Sudowoodo, Sunflora, Sunkern
T: Taillow, Tapu Koko, Tauros, Tentacool, Tepig, Terrakion, Timburr, Tirtouga, Torterra, Tropius, Typhlosion
U: Unown L
V: Vanillite (Dynamaxed), Vespiquen (Dynamaxed), Volbeat
W: Wailmer, Wailord, Walrein, Wartortle, Watchog, Weavile, Weepinbell, Wynaut
Y: Yamask, Yanmega
Z: Zigzagoon
Legend:
Bolded = Legendaries, Mythicals, Ultra Beasts
Italic = Obtained in a trade
underlined = B-day
Colored = Shiny