There are a lot but here are just a couple of mine! I am re-watching 1x03 on YouTube and the part when Castle is watching Alexis sleep and when she wakes up he tells her how he always watched her sleep and then asks if she does drugs and about her friends. Good scene! I would also have to say one of my favorite scenes is when they are playing Laser Tag. Sorry, the name of the episode escapes me!

I love almost every scene she has with Castle but I really liked the one in 4x22(I think) where Castle is dressed as a zombie and have their "last fight"

I know... there are so many great ones of Alexis! :) I love all her wisdom that she gives Castle! I liked the one in season 2 premiere "Why can't guys just say they're sorry"! Alexis is so smart! I also loved her speech at the end of Season 4 - that was awesome!!!
"Today we say goodbye to everything that was familiar, everything that was comfortable. We're moving on. But just because we're leaving, and that hurts, there's some people who are so much a part of us, they'll be with us no matter what. They are our solid ground. Our North Star. And the small clear voices in our hearts that will be with us … Always."<3

Graduation Speech was my fave in fact. She was so mature on it!!!

I agree with with you drewjoana, she proved to be mature through the whole series in every episode, but that moment at her graduation and the speech she gave it was really remarkable, i just graduated from high school too and I totally get what she was saying

I used to like Alexis so much more in the first 3 seasons ,then in S4+5 not that much .... my favorite moment has to be when she was working as a volunteer at the pricient and she found an old album with photos + returned it to the family ,such a beautiful scene.