homer's mini-speeches are really the best. 2 examples:
"Never, Marge! Never. I can't live the button-down life like you.
I want it all: the terrifying lows, the dizzying highs, the creamy
middles. Sure, I might offend a few of the bluenoses with my cocky
stride and musky odours. Oh, I'll never be the darling of the
so-called 'City Fathers,' who cluck their tongues, stroke their beards,
and talk about, 'What's to be done with this Homer Simpson?'"
"Look, Marge. You don't know what it's like. I'm the one out there every day putting his ass on the line. And I'm not out of order. You're out of order! The whole freakin' system is out of order! You want the truth? You want the truth? You can't handle the truth! 'Cause when you reach over and put your hand into a pile of goo that was your best friend's face, you'll know what to do! Forget it, Marge! It's Chinatown!"
not really a speech, but still sticks with me.
"Please, please, kids, stop fighting. Maybe Lisa's right about America being the land of opportunity,
and maybe Adil's got a point about the machinery of capitalism
being oiled with the blood of the workers."
and everyone's right, there are countless examples. all you can hope to do is recall your memorable ones.