My fav C/A moments are so much the ones already mentioned but off hand my 2 favorites are the end of "Your Welcome", the kiss and looks it was all so real and made me realize why I fell in love with C/A in the first place
I also loved the end of TSILA. I love Angel's "I want you back, I need you back" to me this started to define their relationship and show how much Angel truly cared for and needed Cordelia.