Dean:
The back of your neck
He likes to walkup behind you and kiss it.
Sam:
Your lips
When you lay together for a while he just rubs his thumb along them
Castiel:
Your eyes
He likes to look into them and figure out what your thinking or just stare
Lucifer:
Your chest:
He likes to put his ear against and listen to your heart beat
Gabriel:
Everything
He kind of likes to “worship" you every chance he gets
