-game of thrones references:
Longclaw, the name of Jon Snow sword
Dead dwarf in skycell, reference to Tyrion lannister imprisoned
-Supernatural (TV series) references:
salts on the floor, a parody to Supernatural lore that salt makes wraiths or spirits cannot pass it.
-Snow White reference in isle of the mists quest
-Lambert teasing Geralt about "killing monsters" one liners from the Witcher 3 trailer
-3 trolls with the name of possibly CDPR favorite gaming youtubers Joe, Dogder, & Jesse (Angry Joe, Dogder, & Jesse Cox)
-GOG.com grimoire about DRM free games
-Atlantis myth, Ciri dialogues with Geralt about her living in underwater city for quite sometime
-Starship Troopers planet? Geralt visiting a wasteland with endless insectoid species (no humans)
-Picasso art "The naked woman" while Geralt meet certain person