One of the Guardians chastises Hal for punching the viceroy of an alien planet in the face. Hal objects to that, saying he punched him in the stomach, then headbutted him in the face.
Rev not knowing what a secret identity is and Kilowog's explanation:
"That's Hal's hangup. That thing on his face, it's a mask. He wears it in case some Earthling climbs aboard the Interceptor, while we're in space mind you, and says 'AHA! THE GREEN LANTERN ON MY PLANET IS HAL JORDAN! I'M TELLIN' EVERYONE!'"
Hal's retort is pretty funny too:
"Talk to me when your planet invents paparazzi and the 24-hour news cycle."
When Hal is about to break into a space prison with Kilowog, he tells the alien creature they captured that dinner will be in two hours, and if they don't come back "start without us because we are probably dead."
Carol points out that "Yeehaw!" doesn't exactly transcribe to on an after-flight report and asks for words. Hal obliges.
"Plane go fast. Very fast. Plane goooood."
Hal's failed attempt to get past the Interceptor's security surely qualifies. It involves him making a wobbly construct of Ganthet and poorly imitating his voice. Security isn't fooled.
Saint Walker: That is not a very pleasant name. Not in the least.
Especially that it's technically a Mood Whiplash, as right before this quote Saint Walker was talking all serious about how the ships crashed due to their doomed goals, and then just becomes all pleasant immediately afterwards.
His and Razer's entire fight has shades of this, Razer's going all out simply trying to land a single punch on Walker, who in turn is dodging everything with ease and treating the whole situation more like the two are simply out on a friendly stroll.
"Uh, Master, permission to cut off Razer's head?"
In "Regime Change", Ganthet creates a Blue power battery just in time. Cue Hal, Iolande, and Kilowog getting massive power-ups... and Razer's ring blinking out, leading to him plummeting several hundred feet from the air. Screaming.
Razer gets his ring shut off by the Blue Lantern battery, and the scene with Aya having to rescue him is played like an impotence joke.
After successfully saving his crew, getting the code from thanagarians, and getting the Red Lanterns off their backs, Kilowog says they even got to keep a deceased guardian's ring, only to discover that Byth Rok (the thanagarian leader) stole the ring off his hand. Kilowog has a brief, but still hilarious reaction to this.
Kilowog: That, that thief!
Byth Rok's death was pretty brutal, but the prelude to it has some funny scenes:
Atrocitus: Tell me the code to the Lighthouse. Now.
Byth Rok: For two thousand...
Zilius Zox: Money? You dare haggle with Lord Atrocitus as if he were a stinkin' lop fruit vendor?
[Byth Rok is electrocuted]
Byth Rok: ...one thousand?
Zilius Zox: [Beat] ...he did come down 50%, Master. That's a pretty good deal.
Zilius Zox's frantic reaction after believing that the Guardians realized that they're in command of the Interceptor.
Hal gets to know Guy. At which point Guy says that Hal looks like a fanboy rather than a real Lantern.
Before that, Guy interrupting Hal talking to the reporter:
Hal Jordan: 'Some other'? You really should check your facts. I am the only Green Lantern of...[gets shoved aside by Guy] ugh!
Guy Gardner: Green Lantern of "Ugh"? You'd better get back there!
Also, when they investigate the Manhunter base:
Guy Gardner: Hey, it's my little sidekick. Stay outside, I'll call ya if I need ya. [beat] At never o'clock!
Guy Gardner acts sympathetic towards Hal after Carol ends their relationship because she doesn't want him to choose between her and being a Green Lantern. He then asks about getting Carol's number, at which point Hal punches him in the face.
"Say, is that Guy Gardner?"
Tomar-Re referring to Hal's gut feeling as his "digestive juices".
Hal Jordan vs. Ch'p, the Green Lantern Squirrel. Ch'p wins.
Hal:No mas! No mas!
To put it in context, Hal offers to fight Kilowog's best recruit in order to persuade him to join his Manhunter investigation. Kilowog then reveals he was gonna go with him anyway, he just wanted to watch Hal get his ass kicked by the squirrel.
Kilowog telling Hal his recruits are "Like his children"...and promptly yelling at one at the top of his lungs for doing something wrong.
Hal and Kilowog get introduced to LANOS, who promptly tosses them around for insulting him, all in a very cheery tone.
Ch'p's escape from the science lab being momentarily foiled when a container gets sent through the pneumatic tube he used to get in.
While Kilowog is arguing with Tomar-Re that Hal Jordan is still alive, the man himself calls in to tell them as much. Kilowog snaps at him not to interrupt before realizing the implications.
The Running Gag of no one being able to follow a simple "3, 2, 1" count without a translator.
Hal and Kilowog manage to recharge their rings on a severed Manhunter head. Kilowog then tosses it to Razer, who holds up the head and his ring hand as silent snark.
Hal: That's our ticket inside. When it passes us, we need to slip under the last vehicle.
Kilowog: [speaks in alien language]
Hal: I suppose fashion-plate here has a better idea?
Razer: He says, "That's our ticket inside. When it passes us, we need to slip under the last vehicle."
Hal: Huh, okay. Good plan.
An alien with a means of transport demands payment from the trio. Hal offers some keys, a pack of gum, and a cell phone. Kilowog offers a handful of worms. Razer offers a couple of shuriken and knives. Lots and lots of knives.
It's later shown that those weren't all his shuriken.
Then the alien asks for Carol as a payment, causing Hal to ask the others how to explain him he can't, of course, do that. Killowog's method is... radical, but effective.
"What have you done to Mother?"
Razer's Cherry Tapping the alien at the end of the fight by throwing the Manhunter's helmet at it.
Also, Razer's absolutely deadpan expression when he stares at the camera seconds before Hal grabs him with his ring.
Poor Carol getting pulled to Zamaron in the middle of lunch, complete with tray and tongs in hand. Her reaction really sells it.
When Larfleeze senses the avarice-possessed Hal is taking some of his rings:
Larfleeze: He's touching my stuff! I can feel it! He's touching, touching, touching my stuff! (Angrish) Stop touching my STUUUUUUUUUUUUUFFFF!!! (Barrels off in Hal's direction)
When Larfleeze is finally "reunited" with his battery, he hugs it, falls to the floor, and begins to roll back and forth on his side with it in unmitigated glee, exclaiming, "Oh, how I missed you!"
Larfleeze offering the group a nice reward before they leave. Then a smaller reward. Then a yet smaller one... and a fly. Which he eats instead of giving them. So he just "gives" them his best wishes.
In "Scarred", Kilowog tells LANOS to shut up when he goes on and on about the star system they've just entered. When space turtles attack them and Kilowog complains, LANOS proudly states that he followed Kilowog's orders successfully.
From the same episode, Kilowog accidentally discovering Scar's secret lab after noticing a misaligned planet on a star map and deciding to realign it.
Hal: Thank you, Kilowog's OCD.
There's also Hal trying to break into Scar's quarters using a credit card construct.
In "Ranx," when Hal finds out that Guy was promoted to the Honor Guard:
Hal: So wait, if you're here, then who's the new Green Lantern of Earth?
Guy: I dunno, some other Earth guy, what's his name... John Stewart.