1) Roswell - the one where Max comes back from the future to tell Liz she has to break his heart, otherwise the world will be destroyed.
This is one of my favorite episodes--not just scenes--of all shows, ever. Future Max is super hot and all badass, so that's fun, but mostly I loved this episode because it was so freaking heart-wrenching. Future Max has Liz break up with him so he can fall in love with the girl he's destined for? So sad! I totally cried like a thirteen year-old girl.
2) TVD - Damon professing his love for Elena and then erasing her memory. CLASSIC!
3) Smallville - The one where Clark rescues Lex from the lab after Lex and Lana get married
4) Buffy - The one where Angel and Buffy trick Faith
SCORE!!!! It's scenes like this that made Buffy so awesome! Bravo to Angel for his stellar trickery skills and great portrayal of Evil Angelus. And much applause for Buffy in her ability to keep her hands "tied" when Faith punched her. Awesome episode--great twist. I totally didn't see it coming. I mean, sure, it was eventually the reason Angel and Buffy broke up, but whatever. It was still rad.
5) The Secret Circle - The one where all the birds die. You know what I'm talking about. ;)
Anyway, those are my top five CW moments! Do you guys have any personal favorite TV moments? :)