Hun: Why do you keep doing that?! Who are you talking to?THERE'S NO ONE THERE!!!"
Mikey and the 1980's turtles battle cries.
Leonardo: Uh... so, how do you guys normally handle these situations?
1987 Turtles: Turtle Power!
Michelangelo: Don't ya just love these guys? Cowabunga! *joins along with the 1987 Turtles*
1987 Turtles: Cowabunga!
Raphael: *moans* Geez, it's like having Five Mikeys now!
How about people being attacked by a giant walking-talking banana. That's right a giant banana, I know... weird.
2003 Raphael: Was that a mutant... banana?
2003 Michaelangelo: This dimension is SERIOUSLY messed up.
The two Mikeys banter in battle.
87 Mikey: Cool off, dude.
03 Mikey: Cool off he says.
During the fight with the foot soldier army, 2003 Raphael was having the time of his life destroying a huge number of foot soldier robots, then his rampage gets cut short by 1987 Donatello who wastes his intended targets with a boulder.
2003 Michaelangelo: Bro, I could tell you stories.
One of the cut scenes features the two teams (mostly just Raphael on the 2003 team's part) arguing about which Shredder caused the problem in the first place. Casey and April's expressions say everything that needs to be said, topped with this line from Casey:
"Your doubles ain't exactly playin' with a full deck, are they?"
This is funny in itself, given that 1987 Casey was essentially Harry Callahan in hockey gear.
The 87 Turtles upon returning to their dimension.
87 Leo: But first, we have to save April!
87 Don: We save April at least once a day.
"Wait! Come back with my command chair!"
The 87 and 03 Turtles get rid of Shredder-Prime... By pelting him with rubbish and knocking him off the rooftop they were on.
If he survived the fall, Shredder-Prime probably walked away from the battle very confused.
In the first appearance of the Turtles-Prime, while they're attacking their inter-dimensional counterparts, we get this exchange:
Leo-Prime: (narrating) I strike two on my way down. Donatello takes out a third with his staff. Already, the pudgy ones are starting to panic. Raph loves this stuff. He's not alone.
03 Don: Why is he narrating? Is he crazy?
03 Mikey: Hardcore crazy.
03 Raph: I love these guys!
The exchange between the two Turtle groups with the Mirage Turtles.
Mirage Michaelangelo: ... So you're supposed to be us... from other worlds. (Beat) I don't see it.
Mirage Donatello: What's up with the multi-colored headbands?
Mirage Raphael: Hmph... sellouts.
2003 Raphael: Yeah, well, check out the initialized belt buckles on these yahoos! (picks up 1987 Leonardo)
1987 Turtles: Hey!
2003 Raphael: I mean how lame can a turtle get? Am I right? (holds up his hand for a high five. Mirage Raphael slaps it away, puts him in an armlock, and kicks him away) Hey! OW! Geez, what a hardcase... (1987 Turtles smile and chuckle) What?
1987 Turtles: Nothing.
This line from Krang when the Utrom Shredder uses the Technodrome's multiverse viewer:
Ch'rell is visibly scared when the Mirage Turtles are on his window in his armor; take into account that the Mirage Turtles scared the crap out of the most dangerous Shredder out of the core three. Actually when you take it quite literally, this Shredder is the most dangerous Shredder period that has or ever will exist. Because no Shredder could make a plan that could outdo destroying all reality.
2003 Mikey's initial reactions to the 1987 Turtles and their opponents. That and a brief exchange with his counterpart on 2003 Raphael's attitude.
2003 Mikey Tempting Fate by asking his counterparts if the Turtle Blimp can go any faster. He knows he shouldn't have asked, after what happens next.
Did I bonk my head, or am I seeing double?
The Soap Opera that Master Splinter was watching. Watch out for his reaction.
"I'm not your stepbrother—I'm your half-sister!"
Who is responsible for the final defeat of the Utrom Shredder, by far and way the most dangerous Shredder in the history of the franchise, and saving the multiverse? It wasn't the Turtles, it wasn't Splinter, hell, it wasn't the 1987 Shredder, Krang, or even Karai (even though they all played a part). No, it was Bebop and Rocksteady.