My favorite reference from Ready Player One, is Toshiro Mifune. Not that it's exactly subtle, since the character of Daito's real name is Toshiro. But it was cool to see that Daito's mask is Mifune's face; it was the kind of pop-culture reference I was not expecting. I'm assuming that came from Spielberg and not Cline.
That said, I really disliked how this movie felt like it had to explain most of its references. If anyone cares that it's the bike from Akira, they'll know it. In general this movie seems to assume its viewers are rather dumb and need everything explained, even when the visuals are doing a fine job. Which is a bit ironic for a movie that seems to be targeted at and audience that should be very visually literate, and wants to find the Easter eggs.
I can understand the need for some narration, but perhaps this could have been done in a vlog style, or as a gamer making videos for his channel. In itself it could have referenced pop culture.