The "Oof" feeling

I read romance for that feeling that I get, right behind my sternum, when two characters really connect, when one character exposes themself emotionally to the other, when things are intense and totally on the line.  Okay, I also like the parts of a romance that cause that "ooooh" feeling a little lower down, but really, I would read just for the "oof", and if I don't get the "oof", the "oooooh" isn't going to happen.   I don't know what to call it, besides the "oof". 

My friend Mary just sent me the first love scene from her NaNo WIP, and I got the "oof", from just a few dozen words.  That is so cool! I SO want to be able to nail that. 

How does that work?  I know that it has alot to do with the whole "Show don't Tell" thing working in sync with deep POV. 

What are the best examples of the "oof" feeling out there?  One that comes to mind is from An Officer and a Gentleman,  when Paula blows up at Zach for being emotionally locked down and she tries to leave their motel room. She can't get the door open, and he jumps off the bed and stops her from going.  He has to break his "I am an island" protocol, and admit that she's important to him.

Another favorite of mine is in Hot Target, by Suzanne Brockmann.  Cosmo has bailed on his bodyguarding job because he thinks Jane is going to be getting with another guy; and she calls him to ask him what his problem is.  He says he didn't want to be there while she was, you know, and she realizes that "you didn't leave because you don't like me, you left because you DO like me!" I'm paraphrasing, but that's the jist. Then Cosmo comes back over, and there is a long complicated scene where they are both kind of paralyzed about getting together because they both want it so bad.  Sigh.  I love Cosmo. 

And I just love me a good "oof".