Miguel and Tulio are stranded in the ocean on a rowboat with Altivo
Miguel: Did you ever imagine it would end like this?
Tulio: The horse is a surprise.
While sitting in the rowboat, a seagull dies on one of their oars. When the starving duo reach for it, a shark pops up and steals it with a huge crunch, and they are just frozen at the unfairness of it all. Hilarious.
Any of the "duel" scenes:
Tulio: I will give you the honor of a quick and painless death— [pulls a tiny dagger from a guard] —But not with that. [switches it for a rapier] I prefer to fight fairly!
Miguel: Oh, you fight like my sister!
Tulio: I... fought your sister - that's a compliment!
Or when Miguel realizes that some landmarks on the island match up with the map they won/stole:
Miguel: You said it yourself it was possible, and it is! It really is! The map to EL DORADO!
Tulio: ...You drank the seawater, didn't you?
"You kept the map, but you couldn't grab a little more food?!"
Tulio tries to get Miguel to stay away from Chel:
Tulio: The little voice? Remember the little voice? Just for a second imagine that you have one. What would it be saying about Chel?
Miguel and Tulio's first test as gods in El Dorado, involving the conveniently erupting volcano.
Tulio's Big Word Shout causes all the smoke to retreat back into the volcano and it lets out a cough.
Tulio: What's happening?!
Miguel: [deadpan] We are both in barrels, that is the extent of my knowledge.
When they're about to leap into those barrels, Tulio bets Miguel they won't make it. When they do, there's a cheerful "you lose!" from inside Miguel's barrel, and a pair of coins are flipped out of Tulio's into Miguel's as Tulio promptly pays up.
After the duo is found and dragged before Cortez, he coolly informs them that they will be flogged, locked up and brought along to Cuba, where they will be flogged again and used as slave labor for the rest of their lives.
Miguel: "Do you think Cortes could have gotten here before us and—"
Tulio: "And what?! Taken all the really big rocks? The scoundrel!"
A few funny scenes come from the duo's imprisonment in Cortez's brig. For example, Tulio's plan on escaping, which he comes up with after spending a lot of time in the brig literally banging his head against the wall.
Tulio: Here's the plan. In the dead of night, you and I, grab some provisions, hijack one of those longboats, and then we row back to Spain like there's no maņana!
Miguel: Back to Spain? Yeah?
Miguel: In a rowboat?
Tulio: You got it.
Miguel: Great. Sensational. And, and that's, that's your plan, is it?