These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Crowning Music of Awesome: "Dance of the Robe," "The Gods Love Nubia," "Fortune Favors the Brave," "My Strongest Suit," "Like Father Like Son," "Written in the Stars," "Every Story is a Love Story," just to name a few songs. Basically, almost all the music in Aida is this.
Painful Rhyme: "A stranger I just met/ A woman whom I barely know at all and will forget."
Also the whole premise of the song "Like Father, Like Son."
Radames: I've done wrong I can't deny.
But at least I know that I
Shouldn't blame that on my stock.
Well this may come as quite a shock!
But I'm no chip off any block!
"Just like me he's found that flesh/Can excite but will enmesh"
Strangled by the Red String: The transfer between captor and slave to secret lovers between Radames and Aida was not very smooth. They just sort of spontaneously stop hating each other.
Not so much on Radames part—it's established from the beginning that he has at least a grudging respect for her and he sends her and her friends off for the easier positions of handmaidens rather than dangerous work in the mines. Plus, his efforts to change for the better are clearly an attempt to impress and woo her.
Unfortunate Implications: Radames removing his shirt, in a clear attempt to intimidate Aida into thinking he's about to force himself on her—then commanding her to wash his back, something which essentially symbolizes exactly that. Later, during an argument, she snaps that he can't force her to show him affection, to which he basically responds, that yes, he could—again, the threat of rape. Yet within a few minutes of this conversation, they're singing a love duet and she's (willingly) falling into his arms.