I'm sure there's more but here's all the ones I can remember:

Baroness von Bon Bon (Cuphead)

Jim Halpert (The Office) (Kind of)

Strong Bad (Homestar Runner)

Meiko (Vocaloid)

Rachel Bighead (Rocko's Modern Life)

Flower, Four, and Lollipop (Battle for Dream Island)

Paintbrush and (kind of) MePhone4 (Inanimate Insanity)

Kaeya (Genshin Impact) (I'm not in this fandom but I've played a little bit of the game)

Jeff Winger (Community)