Portal Fancast (Chell, Rattmann, Cave Johnson, Caroline)
This cast has Ella Purnell as Chell, Mark Duplass as Doug Rattmann, Christopher Lee as Cave Johnson, and Jennifer Garner as Caroline.
If you have any suggestions, please put them in the comments! a few have already been made:
David Tennant: Doug Rattmann
JK Simmons (not him currently, younger JK Simmons): Cave Johnson
u/CarolineJohnson: Caroline
EDIT:
Everyone in this comment section needs to realize that I am just making this post for fun. I'm not directing a portal movie, I'm not reaching out to these actors (one of which has passed away now), it's just a post to show that some of these actors look like the characters. It's completely unnecessary to bring up the death of Christopher Lee, and nitpick every little detail.
I also want to make it a point to say that I DO want other suggestions, and I DO want discussion, and if you have an idea for a different actor, PLEASE post them in the comments. I want to see them. What I do not want is for people to be unnecessary and rude, which I know isn't technically preventable, but please just don't do that.