Ah... some of my favorite romance movie scenes...
The scene at the end of Untamed Heart where Marissa Tomei's character reads the letter and plays the record.
The corny, but completely aww moment at the end of Jerry Maguire... "You had me at hello"
The end of When Harry Met Sally ... "When you've met the person you want to spend the rest of your life with, you want the rest of your life to start right away" (or something like that)
I know CaliGirl will hate this, but I love the scene where Ewan McGregor comes back at the end and signs "Come What May" in Moulin Rouge.
And of course the boombox scene in Say Anything
I'm sure there are more, but those are ones that are coming to mind right now.