Here are some of the best lines between and about Quinn and Finn from the 2x19 episode "Rumours".
“Oh, I trust you. I just don’t trust her.” - Quinn
“I love being here, and I wanna win, but my relationship comes first. I’m sorry but Finn, if you wanna be with me, no more songs with her.” - Quinn
"I don't want to know the reasons why love keeps right on walking on down the line." - Finn and Quinn in their duet
"Now that's garbage. Quinn's clastrophobic." - Finn
"Sam's not gay." - Quinn
"Don't you think it's inappropriate for you to be singing a love song to my guy?" - Quinn
"What were you doing with him in that motel?" - Finn