Somebody's Going To Emergency, Somebody's Going To Jail (Episode 216)
First Aired: Wednesday, 28th February, 2001
Writers: Aaron Sorkin and Paul Redford
Director: Jessica Yu

While technically not a Josh and Donna scene, their interaction when Josh takes his Big Block Of Cheese Day assignment from Donna demonstrates their ability to speak entire conversations without saying a word.

This scene is not really about Josh and Donna either, but I thought it gave some insight into their relationship.

I Appreciate That
White House mess / stairway. Sam, Donna and Stephanie sit at a table as Josh approaches.

JOSH: Hey Steph.
DONNA: You're across the street in five minutes.
JOSH: Yeah.
SAM: (to Josh) I'll walk out with you.
STEPHANIE: Sam, thank you.
SAM: Yeah. (he and Josh leave)
JOSH: You on the Gault thing?
SAM: Yeah.
JOSH: That's nice of you. I appreciate that.

Toby And I Are Going To Get Sam Drunk, And Then Put Him To Bed
Sam's office. Sam and Donna talk as Josh and Toby enter.

JOSH: Hey. You should have seen Toby.
SAM: He was good?
JOSH: He blew the doors off the place. Then I almost got killed.
JOSH: I got hit with a piece of a banana.
TOBY: Let's go.
JOSH: You know what you are? You are old school, my friend.
TOBY: Stop talking like that. Let's go.
JOSH: Let me tell you something, though. That was the second time this year I almost got killed and both times I was with you, so you're going to need a new wingman.
TOBY: You were my old wingman?
JOSH: Yeah.
TOBY: Let's go.
DONNA: Where are you going?
JOSH: Toby and I are going to get Sam drunk, and then put him to bed.
DONNA: I'll come.

Many thanks to The West Wing Collection for the wonderful screencaps!