Wario and Yoshi are probably the best convos, but I'll post the three convos here anyway, just because their so well-thought out in my opinion. Plus, I need an excuse to use quotation marks. 😛
Yoshi (Otacon):
"Otacon, what's this lizard thing?"
"That's a Yoshi. It's a dinosaur from Yoshi's Island."
"Watch out for its long, chameleon-like tongue. If it gets you, you'll be swallowed whole."
"It lays eggs and throws them, right? ...Then it must be female."
"...Actually, it's a "he". At least, that's what it says."
"It talks?!"
"Yes, it talks! Well, kind of..."
"Now you got me curious. ...How about I capture one so we can see what they taste like."
"Uhh, Snake."
Wario (Colonel):
"This guy kind of gives me the creeps."
"That's Wario, Snake."
"Wario first appeared as Mario's rival, but he really made his name in the WarioWare games."
"Watch out for Wario's bite. It's not just damage you take from it."
"What do you mean, Colonel?"
"Wario loves garlic. He eats whole cloves of it day and night."
"So try not to get caught in his mouth. Once that smell gets on you, it'll stick to you for quite a while."
"...That's a scary thought."
"He also attacks by farting. He can fart to fly around, too."
"By farting?! Are you kidding me?!" (Snake sounds a bit pissed off here)
"Sadly, no. I am not kidding. If his belly starts to bulge, watch out."
Samus (Mei Ling):
"Mei Ling, Samus took her clothes off!"
"That's just her in the Zero Suit, Snake."
"Without that bulky Power Suit, she's gotten a lot more agile..."
"You know, I bet if I took off all this heavy gear, I could catch her..."
"Um, yeah, you wish."
"Even without the Power Suit, all that training she did with the Chozo has made her a super athlete."
"I don't think a normal human could ever keep up. Just look at her."
"...Her loss."
One last note, if the screenshot with RAY in it doesn't scream "EPIC", then nothing in this game will.