All I want out of Portal 3 is an extended intro-sequence with a bunch of human NPCs who Chell is on friendly terms with, where Chell basically doesn't shut up, as per Erik Wolfpaw stating that Chell doesn't talk in the games because she didn't want to give GLaDOS the satisfaction of a response
Actually, no, what I really want is to have Chell, 2/3 of the way through the game, to just go "God, you talk too much" at whichever computer is in control of the Enrichment Center, and then GLaDOS spends the rest of the game trying and failing to get her to talk again. It was premeditated. Chell knew that she could only do this once.
Alternatively: Chell does speak freely in front of GLaDOS when other humans are around, but never to GLaDOS. Like GLaDOS sends in a probe, Chell's like "yeah this is her"/says she's leaving, but you have to make her face away from GLaDOS to talk. Everyone's like "oh now I get it, they're exes", Chell and GLaDOS both go "NO!" at the same time