Well it was definitely the funniest episode thus far. Though honestly it could have just been 40 minutes of CJ talking with cotton in her cheeks and it still would have placed highly.
Josh: Sam went to Foggy Bottom.
CJ: What's he doing in Foggy Bottom?
Josh: (laughs) I'm sorry. I just wanted to see if I could make you say Foggy Bottom.
Josh: Hey there cats and kittens, this is Josh Lyman coming at you with your two o'clock briefing!
CJ: Josh please! Be very careful. Try very, very hard not to destroy us.
Josh: You shouldn't say that, CJ, you've got a great body.
Josh's interaction with Danny right after that was hilarious as well, and Danny's look to Josh at the end of the briefing was perfect.
Sam, as he has the last few episodes, was great in laying down the law to anyone that crosses him.
Sam: Officer Peter, we're in a certain amount of trouble tonight, and the only thing I've gotten going for me is that you're in more trouble than we are. My name is Sam Seaborn, I work for the President, and the sooner you reach the conclusion that I'm telling you the truth the better off we're all gonna be. Why don't you go get your watch commander.
Toby was excellent as well in his scene with Mendoza,
Toby: Nothing about this that doesn't stink. And nothing about it that wouldn't be better if you were a Supreme Court Justice.
Charlie also endeared himself a little more to me. Having to wake someone up is something I truly dread doing. I guess its just a combination of feeling bad for them and knowing that the best possible reaction I can hope for is them not being completely pissed off at me.
Bartlet was on point as always
Bartlet: I'm tired, I'm cranky, and my wife's in Argentina. Lets get this over with.
I think what made this episode so good was that we got to see a problem unfold from beginning to end, and see each member of the staff's role in fixing it(or in some of their cases making it much worse).
Celestial Navigation may not be my favorite episode(The Crackpots and These Women still holds that spot), but it definitely made my top three(so far).