Hello!

Encountered this reference to Grundy in AO. There's a building called "Gotham Casinos" (the "S" at the end is included in the building name). When you are facing the building, the poster is to the left. I had to use imgur because of GoG forum restrictions.

https://imgur.com/a/m28D5Fj

Just found another one for Basil Karlo (Clayface)

https://imgur.com/a/0ziCAqA

Green Lantern reference "Ferris Aircraft".

https://imgur.com/a/oL56ivq

https://dc.fandom.com/wiki/Ferris_Aircraft

Wonder Woman reference - Cale-Anderson Pharmaceuticals

https://imgur.com/a/nW1Z250

https://dc.fandom.com/wiki/Cale-Anderson_Pharmaceuticals

Poison Ivy

https://imgur.com/a/8Gu2Fpr

https://arkhamcity.fandom.com/wiki/Baudelaire_Flower_Shop#Trivia

Doctor Penelope Young has an apartment in Lacey Towers

https://imgur.com/a/CKl8uLb

There is a reference to Queen Industries on of the crates of The Final Offer. I forgot to take a screencap of it.