I think if I had to pick one location, I would live by the ocean. I enjoy the possibilities of looking out over the water, feeling like I'm standing by something endless.
Don't get me wrong, both locations have their perks. One of the best parts of going to the mountains, is feeling apart from everything. You can see the stars, and they feel close enough to reach up and steal. I sleep soundly in both locations due to the natural soundtrack all around (waves crashing, bugs and breeze). Both locations feel amazingly fresh, and have air of their own. Both places feel like time stops for a little while, because the only real reminder of time passing is the sun and moon.
I suppose I make both seem a little fantastical, but that's just how I roll.