*Being such a huge fan of Oklahoma! and the original cast recording, seeing Joan Roberts sing "One More Kiss" in the revival of Follies was chilling.
*Vanessa Regrave clawing the walls in Long Days Journey Into Night
*Edie Falco's performance in Frankie & Johnny. Her's was the best performance I've ever seen onstage and by far the best of that season (and yes, I did see Ms. Redgrave's).
*All of The Goat, or Who is Sylvia?, particularly Mercedes Ruehl's performance--when she delievered the line (and I'm paraphrasing) "You have brought me down and now I will bring you down", my heart absolutely stopped (why oh WHY did she not win the Tony that year?!?! Can anyone tell me?!?). Also the big scene between Bill Pullman & Jeffrey Carlson near the end--so incredibly raw & real--I was shaking.
*Andrea McArdle, on tour, slamming down the microphone at the end of the title song in Cabaret (she was dreadful in the show but that moment was jarring).
*The first time I saw Stephanie D'Abruzzo sing "Fine Fine Line" at the Vineyard Off-Broadway. The night I saw it she really played it for anger and it was spellbinding. I've never seen or heard it that good since.
*The 'moment of silence' in Big River. Also, Michael McElroy & Ty Giordano doing "Worlds Apart."
There are more, but these are the most fantastic.
"I'll eat some breakfast then change the world."
"I hate you, and I hate your ass face!"