J: Great. Abso-fudging-lutely great.
Translator microbes, the Hays office of the Uncharted Territories.

J: If we're gonna go down, I wanna go down swinging.
To "go down swinging" or "go down on a swing" is a metaphor from that most American of sports, baseball. The following quote is from an article at Ask Mr. ESL.

"So the expression "to go down swinging" means to fail at something after intense effort. The person who "goes down swinging" is not one who is resigned to the negative outcome, or who quits without trying."

J: Yeah, but what if one of us did the same thing, but at the last second veered off straight into the bridge? A Trojan Horse.
Aeryn and D'Argo don't react to this last Earth cultural reference; I figure either the translator microbes got that one okay or the crew has just started ignoring John's odd sayings.

definition of Trojan Horse
noun
1. A subversive group or device placed within enemy ranks.
2. The hollow wooden horse in which, according to legend, Greeks hid and gained entrance to Troy, later opening the gates to their army.
~ courtesy of Dictionary.com

Z: John...I've made new family here, surrounded by all of you. And now I sense it's coming to an end.
J: Well, it's a...Jerry Springer kind of family. But for what's it's worth, Zhaan... you are family.
Jerry Springer is an American talk show host known for his weird and often perverse (or perverted) guests.

J: How are you doing?
Crais: Why would you ask?
J: I look at you...and I get homesick. I'm desperate for human, male-to-male conversation. And I figure cars, football...they're out of the question.
Poor John, this scene always gets to me. I can't imagine how truly lonely he must be at times. Sure he's got people who care about him in the Uncharted Territories, but to have no one to talk to who can share his frame of reference prior to 3 years ago must be awfully isolating. There's no way for him to have a conversation about sports or cars or any other Earth-subject without a lengthy explanation preceding it. Even then, no one is really going to be able to relate. How scary for John to feel that way, like he's losing grasp of the things that made him who he is. *sniff*

In response to Chiana's efforts to 'thank' him--
J: Never before the big game. Hm? But thanks.
"Never before the big game" the advice of every high-school or college sports coach since the beginning. After all, sexual activity might sap a player's strength or, at the very least, distract him from the all important of the game about to be played.

C: You saved my life.
J: Pass it on.
C: What?
J: When someone else needs it, return the favour. You pass it on.

J: Well, you're a material kind of guy Rygel. Have some material.
Can't you just picture Rygel in a bright pink evening gown and diamonds singing "We are living in a material world, and I am a material ... slug?"

Zhaan is performing a send-off ceremony--
D: I hate this stuff.
J: Chicks love it.
"Chick" is an American slang term for a woman.

J: Leader bogeys on the way. Fly faster, Rasta Man.
D: If I could fly any faster, don't you think I would?
J: Just a figure of speech, D'Argo.
D: Figure less, speak less.
"Rasta Man" is a reference to the religion of Rastafarianism, a religious-cultural movement that began in the 1930s in Jamaica. Bob Marley was a Rastafarian. I think John's referring to D'Argo's dreadlock-like tentacles.

J: I love hanging with you, man.
"Hanging with" means spending time with someone, socializing.

John and D'Argo are about to punch out of the airlock--
J: You're a good Spock. (Laughs.) Abbott and Costello. First base.
Spock, played by Leonard Nimoy, is the science officer and best-bud of Captain Kirk on the original Star Trek television series. We also revisit the famous Abbott and Costello "Who's On First" comedy sketch first mentioned in "A Human Reaction."

The oil sea bursts into flame--
J: Hey, you bastards. John Crichton was here.
This phrase refers to a form of grafitti popularized during World War II, "Kilroy was here."